Coast (2005) s02e08 Episode Script
Felixstowe to Margate
1 I'm on a stretch of coastline that dominated by one huge estuary.
There might be nothing here today except majestic emptiness as the Romans hadn't liked it so much they established a trading post and called itLondinium.
I'm going to discover how that moment in hsitory defined England's capital coast.
And to help make sense of it all, we've our usual team.
Nick Crane goes in search of a mighty river and its violent inhabitants.
I don't believe it! Mark Horton seeks out where London's coast ends and the Thames begins.
Alice Roberts gets hands-on experience of one of Britain's first jobs, making salt.
Miranda Krestovnikoff has a close encounter with the remarkable thornback ray.
Watch the thorns, right! I'm going to discover the story of an abandoned time bomb, big enough to rock the entire Thames estuary.
This, of course, is Coast.
The latest leg of our journey takes us from Felixstowe in Suffolk to Margate in Kent.
And there's a little diversion to London.
This stretch of coast has seen repeated waves of tribal settlers that have helped forge our national identity.
Saxons, Jutes, Vikings, Danes.
They all came here, you know.
They were so impressed, they all decided to stay.
But our ancestors never got round to colonising this headland.
Until recently, it was mostly a marsh, but now, it's Felixstowe.
The UK's largest container port.
I'm going to see what one of those is all about.
95 per cent of the goods we consume on our island arrive here by sea.
So when you're shopping, it's odds on that you're buying stuff that came here by ship in boxes like these.
In all, 40 per cent of Britain's trade comes through this port.
Much of that trade once flowed through London, but it moved here because Felixstowe can take bigger ships.
These containers come from every corner of the world.
There are about 6,000 of them on that ship alone.
On the biggest vessels, there are up to 10,000 containers.
Each crane must unload a box every minute, day and night.
Felixstowe handles nearly two million containers per year.
Some of the contents aren't always what they appear.
Stopping smugglers using any one of these incoming box is a Herculean task.
How on earth do they do it? Hi, Kevin.
'Kevin Sayer is one of the few people with the power to open any box.
'Our first container has come from Africa.
'It's suspicious, but they won't say why.
' Is that typical? It looks so completely harmless.
That's what the criminals and the smugglers are trading on.
They want their consignment to look as legitimate as possible.
So it evades our controls.
It does seem a bit odd that it's only half full.
Kevin Do you want to have a look at this? Is there something inside? The X-ray shows a dark block in the image.
It's a black bin liner, Kevin.
It's coming out.
It sounds heavy.
Made a thud there.
Maybe it's the latest Wilbur Smith! Bin liner within a bin liner.
That even looks suspicious to me! This looks like cannabis resin.
That looks like cannabis! Look at that! I can't believe it.
You've set this up just for me.
I wish we could have arranged it.
Is the whole cargo now officially dodgy? Yeah, the whole cargo will effectively be forfeit.
We use a historic phrase "forfeit to the Crown".
What's the Queen going to do with that? It becomes her property.
I'm going away from this with the skewed idea this stuff's popping out of every case.
It's so easy(!) It turned out that our very first container actually had cocaine in it.
Street value, 80,000 pounds.
And that's just a drop in the ocean.
Last year, Customs seized 4.
9 tonnes of the stuff at our frontiers.
Felixstowe port thrives because of the estuary's deep water.
Generally, along this coast, the sea is incredibly shallow and the marshland just merges into it.
All this glorious mud means that it's a haven for wildlife.
Some of it's surprisingly big.
These mud flats are known as saltings, home to an unusual seal colony.
Beneath the layer of fresh grey mud, they've turned a curious reddish colour.
Seals.
Rare common seals.
They're not common to me! No! Oh, yes! Beautiful, eh? 'Tony Haggis is a local guide to these quiet backwaters.
'He visits them daily.
' One of them has a strawberry blonde head and strawberry blonde flippers! What's that about? They go different colours.
Mainly red.
The oxidisation from the saltings turns their coats a rusty colour.
The mud they're on dyes their fur! Where else does that happen? Only in the Thames estuary, I think.
Where we have salt marshes.
These are unique? Yes.
The iron oxides naturally found in the mud stains the seals' coats.
After just two weeks, the young are turned ginger.
Are they reliant on their mothers? They have to suckle from Mum.
They can it do in or out the water.
She has very rich milk.
Within two weeks, the pups put on twice their weight.
All of a sudden, she chucks the pup out to fend for itself then goes and mates for next year.
So what happens? Does she wake up and it's no more Mrs Nice Guy? Sometimes, when the pups have been chucked out, you hear the pups crying and it gets your heart strings.
Nothing we can do.
It's nature.
They have to take care themselves.
Oh, it's terrible! She doesn't want to know any more.
The seal colony is protected from the sea by the headland at Walton on the Naze.
It's on the geological map because of erosion.
The high rate of wear and tear reveals a unique glimpse into our distant past.
Nick Crane likes a little time travel.
There are few places where the coastline changes as quickly and as dramatically as the southeast.
These pillboxes were built in 1940, when this was a clifftop.
60 years of erosion dropped that pillbox onto the beach.
But as well as destroying our more recent history, it's also revealing our ancient past.
Rapid erosion makes Walton one of the finest sites for fossils in Britain.
Gerald Lucy has collected fossils here since he was a boy.
And his finds have taught him how to read the story of this landscape This is London clay, which used to be a mud under the sub-tropical sea.
These are the oldest rocks in the Naze's cliffs.
The rocks get younger as you go up.
If we move up here, I'll show you more.
'Climbing the rock strata at Walton is a remarkable journey through time.
Have you ever found any amazing fossils here? I think the best fossils sometimes are the smallest.
My favourite are sharks' teeth, which you can find on the beach quite easily.
Sharks' teeth fascinate me because they are so common as fossils and they are so exquisitely preserved.
Razor sharp.
And they are 50 million years old.
The sort of thing anybody can find.
This creature is by far not the largest of the teeth you find.
This one here What?! .
.
I have in my pocket! I don't believe it! This is from the creature known as megalodon - Carcharodon megalodon is its Latin name If you make a model of the jaws, and put these teeth in, then you can step into its mouth standing up! You would not want one in your bath! No! Megalodon means "big tooth", they were the largest predator fish ever to swim the sea.
Their fossilised teeth are all that's left.
The super predator was up to 60 feet long.
Studies of whale bones reveal that they featured on a megalodon's menu.
'All that was 1.
5 million years ago.
'Megalodon died out because the waters of Essex became too cold.
'As we climb, the finds become more recent.
' Here is the sandy deposit which is laid down just before the Ice Age, and it's full of fossil shells.
A lot will be found on the beach.
A left-handed whelk.
These shells, some of them are Mediterranean species, and some of them are Arctic species.
As you move up the cliff, the Mediterranean species get fewer and the Arctic species become more common.
It's a definite indication of global cooling as we approach the Ice Age.
'Our journey through time is about to get a little more tricky.
'Walton's cliffs are notoriously unstable so we roped in the Coastguard's expertise.
' Off we go.
All in a day's work! 'The final half yard of cliff was formed in the last 500,000 years.
' What have we got here, Gerald? What we've got here is a layer of gravel.
It's completely different.
This gravel is clearly a river gravel.
It consists pebbles aren't rounded at all.
It's not a beach gravel, it's not marine deposit, so it was a river, a very large river, because the same type of gravel is across much of north Essex and Suffolk.
'Recent studies of these river gravels show that large parts of Essex 'were covered by a vast torrent that dragged rocks here from as far away as north Wales.
'To appreciate the sheer scale of this ancient river 'we need to get some perspective.
' Now there is a huge river, it went right the way across here.
It was much larger than we could imagine.
Amazing! A graded river, many channels, and it was the Thames.
The Thames? How astonishing! What we now call the Thames used to drain from the Welsh mountains, flowing across the country to late join the Rhine in the marshland that is now the North Sea.
But 600,000 years ago, the river's course was blocked by the southerly limit of a vast ice sheet.
When it melted, the Thames burst through a weak spot to find its new path.
If it hadn't been for the ice sheet, the Thames would have been here, London would have been in Essex.
London would have been at Walton on the Naze.
It's amazing what you can discover from a stroll along the beach.
Crowded along this sandy shore are towns that grew up to serve holiday-makers from the capital.
Chief among them is Clacton.
This genteel little town was invented in 1864 as a pleasure beach for well-to-do Londoners.
The introduction of bank holidays and the arrival of the railway opened up Clacton to all-comers.
The town boomed.
MUSIC: "All Day And All Of The Night" by The Kinks By the 1960s, a new breed of Londoner had arrived on the coast.
And they came like this! What a fantastic way to travel by the sea I don't know why I've only had a car driving licence all these years! I want to be a mod as well! But the fun came to a grinding halt on the Easter bank holiday 1964, It was the wettest weekend for 80 years.
There was tension between rival gangs of mods and rockers, two tribes that were about to become infamous.
'The machine they use marks their faith.
For the mods, it's a scooter.
'In the rain, they cover up their elegant clothing.
'Their rivals, the rockers, look the same in any weather: a black uniform for all seasons.
'A rocker needs a motorbike can to a ton to a scooter's 50.
'The difference in power is a matter of masculine pride.
' 'Masculine pride led to fighting.
'The police struggled to keep the peace and the ational press had a front page sensation.
' Scooter gangs 'beat up' Clacton A desperate SOS went out from police "as leather jacketed youths and girls attacked people in the streets, turned over park cars "broke into beach huts, smashed windows and fought with rival gangs.
" Despite the lurid headlines, only 12 youths were prosecuted.
The damage was estimated at 243 pounds.
The true cost was the town's reputation.
Holiday-makers cancelled summer bookings and Clacton nose-dived.
And the mods and rockers? Though the media lost interest, they went on to have punch-ups at the seaside for years to come.
Just south of Clacton is the driest place in the UK.
It gets just over 50 centimetres of rain per year.
By some definition, it's almost a desert.
Combined with all this sea water, it's a perfect place to make salt.
Maldon is famous for the sea salt it produces.
Beloved of celebrity chefs and exported around the world.
A traditional salt factory is the last surviving remnant of a once-thriving enterprise that dates back to pre-Roman times.
Alice Roberts is somewhere on the Black Water estuary, looking for the evidence of our eldest industries The place names in this area show the importance of salt.
We've got Salcott, Gore Saltings.
When the entire British Isles is surrounded by salty sea why is salt so important to this bit of the coast? 'This estuary was once the centre of the country's salt production.
'Mark Atkinson is a local field archeologist who has studied the remains of this industry.
'These banks may look natural, but they're not.
'They are nown as red hills, they're made up of 2,000-year-old remnants of countless terracotta vessels.
' If we look closely, what we have here is an eroding section into a mound of red material.
You can see here we've got estuarine clays on top.
But, from here downwards, a very red soil.
And you can see here, baked clay.
Charcoal here.
Even some Roman pottery here.
Yeah! It's a large area that they were doing this salt-making process over.
This particular red hill is about 100 metres across.
Salt-making, even in the Roman period, was a complex, big and labour-intensive job.
'These pieces of terracotta and the charcoal evidence of fires reveal the importance of this coast to the Romans.
'On a small scale, Mark is recreating this basic industrial method.
'The sun was used to evaporate sea water into concentrated brine.
'This was boiled until salt crystals started to appear on the surface.
'The value of salt to Roman society is still with us.
' There's evidence in the English language that it was prized substance.
We get "salary" from the payment in salt from the Latin for salt.
"Salary.
" Yeah.
And if someone's making a valuable contribution, they're worth their salt.
Yeah! Why was it a precious commodity? Well, essentially, rather than as a condiment, really as a preservative.
Salt was the only means of keeping food fresh or preserved for any prolonged period of time.
So there was this huge industry producing sea salt here.
Why isn't it here any more? I think because it was too time-consuming.
And that the discovery and exploitation of inland salt showed people that this was no longer a good use of their time.
Mining of rock salt takes over from getting sea salt from estuaries like this.
Yeah.
I have to say, with our miniature briquetage evaporation tank, we've made quite a lot of salt.
It's impressive.
It shows that it was an effective industry of its day.
Definitely.
I shall be taking that home for my tea! Across the estuary, at Sale's Point, there's another bounty from the briney deep - This is Bradwell Cockle Spit and it lives up to its name.
' Look, there's one.
There's another one.
In fact, it's nothing but them here.
Millions, gazillions of cockleshells.
The beach is made of them, all be washed here by a confluence of the tide.
'The Cockle Spit is the most northern point of the Dengie marshes, 'a vast sparsely inhabited landscape that's been reclaimed from the sea.
'Surprisingly, these shallow waters off the southeast coast 'are the breeding ground of a wonderfully exotic bottom feeder.
' 'The Thames estuary is home to more than 100 species of fish.
'I'm on the hunt for one with cunning camouflage and vicious armour.
'The thornback ray looks exotic but actually lives within commuting distance of London.
'It's a species that we know very little about.
And there are concerns that thornback rays are in decline.
'I've joined Ewan Hunter, a fisheries expert from Cefas, 'to help with their latest tagging project.
'They're working alongside the fishing industry to find out more about these prettily characters.
But before we get started, we need a freshly caught thornback ray, These are actually the most commonly landed species of ray in the North Sea.
'It's quite likely to have landed on your dinner table at some point.
It's usually sold as skate.
' Ewan, we've got one super live ray for you.
Beautiful.
Can I lift her out? Just be careful with your fingers.
There's a mouth under there.
I'm a real amateur at this! Ooh! Bloody hell! Sorry.
Just watch the tail.
Watch the thorns, right? OK.
Pull her out.
That went right through my glove! Unbelievable.
Sorry, I'll let you handle that.
We're just gonna take two measurements.
We'll start off measure her total length, nose to tail.
Now, this lady is 62 centimetres long.
We'll take a measurement across the wings.
44 centimetres across.
Our biggest females are more than a metre long.
They are a big fish.
Now just taking a look at her, you can see there is Well, I felt them.
Those really ferocious thorns down the back.
They're curved over.
Great defence.
When she's angry, she'll thrash her tail around.
You really have to be careful.
There'd be a lot of blood everywhere! Can we flip her over and look at the underside? Let's just get hold of her here.
Ah, beautiful! Look at the mouth! Can I just feel that? Rows of teeth.
Yeah, rows of teeth! Because they're bottom feeders, so their mouth is on the under side.
Yes.
I'm going to tag her with one of these devices.
That's tiny.
What sort of information does this tag give you? The tag will record depth and temperature every five minutes for about one year.
We can work out where the fish has been between release and recapture with the date from the tag.
Instead of staying in one place, the fish move three times further than we suspected previously.
So instead of staying put the fish are migrating into the Thames during the spring when the fish lay their eggs.
During winter, the fish move right out into the wider southern North Sea, where they tend not to be caught, And this is a migration we were totally unaware of previously.
If you'd not used these tags, you'd never have found out.
No.
It's all new stuff.
'The external yellow marker makes tagged rays easy to spot 'amongst fishermen's catch.
'The surprising migrations revealed by the project will help us conserve the stocks of rays off our coast.
' Is she ready for release? Yes.
I'll let you do the honours.
Come on, girl.
OK.
Back in the water.
There she goes.
We know that the Thames estuary is an important area for these fish.
This tagging project is vital to ensure the thornback rays have a future off our coastline.
So far, I've been travelling south along this eastern coast.
At Southend, I hang a right.
Up there's London, and who can resist that? But, before you get to the big city, you've got to get past its big mess.
London's rubbish gets shipped downstream to Mucking marsh.
Its popularity in Saxon times makes it an archeological treasure trove, as well as one of the UK's largest landfill sites.
It's Lucy Mancer's job to keep on top of it.
It's a nice place to work.
It's hostile, in terms of the environment, but it's a nice PLACE, in terms of people and things to do.
It is a big site here.
It's well over 300 hectares in size.
We take a fifth of London's waste.
Each of our containers takes 12 to 14 tonnes of compacted waste.
We get 20 to 30 containers on a barge, ten barges a day.
'Working here can be very dusty, a bit dirty and occasionally smelly, 'depending on where you work and what we're emptying at the time.
'I don't think my friends and family know the full extent of what I do.
'They know I work in a landfill site 'but they haven't seen the scale of it or the machinery we work with.
' If somebody came back and did an archeological dig, I hope that they would be surprised at the things we throw away, that they would be surprised at the number of carrier bags, as I am.
I'm sure they'd find it interesting, it would tell them about the way we live today.
Just around the river bend is Tilbury.
From here the whole coastline becomes a manmade construction.
Buried beneath are successive layers of our past.
I'm after one event in particular.
It's one of the most legendary moments in all of English history.
On 8th August 1588, Queen Elizabeth I came to Tilbury to rally her troops.
20,000 men, London's last line of defence against the Spanish Armada.
This is it! This is THE Tudor jetty.
Queen Elizabeth I stepped ashore here.
The day is long gone, but the stones that she walked upon when the threat of Spanish invasion was very real are still here.
The speech the Queen made that day is often seen as the defining moment of her reign.
"I know that I have the weak and feeble body of a woman, "but I have the heart and stomach of a King of England.
"And I think foul scorn of Parma or Spain or any prince of Europe "who dares to invade the borders of my realm.
" Nobody speaks like that any more! Travelling the 12 miles upstream from Tilbury into London it's impossible to ignore the ever narrowing estuary.
Where exactly does the coast stop and the river begin? Mark Horton's looking into a tidal conundrum.
When the Ordnance Survey had to define what counted as coast their simple solution was to include everywhere that had a tidal range.
How far does the tide actually extend up the Thames? Is London on the coast? 'I'm going to find that defining point, 'to go where technically the coast stops - it's a journey back through London's maritime history.
'These docks helped make London the greatest port in the world.
'The Royal Albert dock was built in 1874 to be the biggest in Britain.
'This vast complex was necessary to trap the tidal water of the Thames 'and accommodate bigger ships.
'Terry Bowden worked his entire life in the Port of London 'starting in 1938.
'He's the last of a family of river men, stretching back 150 years.
' Are you sad to come back and see this as a leisure place, an airport? I'm sick! I've got a big lump in my throat.
Straight.
It knocks the life out of you when you see it like this.
I loved every minute of it.
We always used to say it was more of a life than a living.
'This massive lock was one of just two ways out into the Thames.
'The vast lock gates trapped the water, as the river dropped 6.
5 metres at low tide.
'For Terry, 'the lock's a reminder of a lifetime spent as a lighterman, 'a skilled occupation, licenced to drive bargeloads of goods around the docks in the river.
'It's an ancient profession that's almost completely redundant.
' You can see over there how low the tide is.
That's right.
Three big wharves there they've flattened, all gone.
Awful.
One of them we called the stinker wharf.
They made bones.
It used to pen and ink when you went by there.
'When Britain ruled the waves, it also made the rules.
'We're crossing from the eastern into the western hemisphere.
'Greenwich Observatory marks the line separating east from west.
'The meridian is here because, when English navigators charted the world 'they decided that Greenwich was the centre of the maritime universe.
' Is that Deptford? That is Deptford.
That's where they hung the pirates up in chains.
Yeah.
That leads up to Leeds Castle where old Henry VIII used to chop the oak trees down, throw them out there up to the Royal Naval Dockyard where they built the ships that defeated the Spanish Armada in the good old days! There's a few docks, mostly filled in.
Oh, yeah.
You've still got Deadman's Dock just there.
When they was digging the docks out, they found all the bodies from the Great Plague buried there, so they call it Deadman's Dock.
Right alongside they built them blocks of flats.
No good living there if you're superstitious! 'Tower Bridge used to stand in the middle of a thronging dock, known as the Pool of London.
'Amazingly, this is also where London has its very own beach.
' 'It was created in the 1930s for the working classes by dumping sand on the foreshore.
'Martha Snooks and Ted Lewis 'remember coming to the beach as a special treat.
' I'm amazed.
You come down here and there's beach sand.
It's not like it used to be.
Sand covered right the way down.
All the way along.
Now, it don't seem true, but it was true.
My dad and granddad were dockers.
That's the family I come from, tough old family.
We never had nothing.
We thought it was the seaside.
Mum told us it was the seaside.
She really believed it herself, that it was the seaside.
Mum used to knit us little costumes out of wool.
They was terrible.
They made you itch.
When you got in the water they used to fall down and end up around your ankles.
Only little children.
Embarrassing! But you must have had barges and warehouses here, Ted.
The river was very busy.
Boats coming up and down, unloading.
Barges.
It was a very busy river.
They must have sat on this beach and looked out watching the boats going out to foreign countries.
That was exciting for us.
We'd go home with a windmill.
Or Mum would buy us a paper umbrella.
We'd put them up and think what a lovely day we'd had.
Oh, I do like to be beside the seaside 'So, if London had a beach, does that make it coastal? 'Time and tide wait for no man, so onwards and backwards, 'to London's very beginning.
' James, can you stop the engines? ENGINES STOP Just feel the tide.
This is the reason why London is here.
This great tideway that brought the ships in, and why the Romans chose this spot as their capital.
'2,000 years ago, Roman sea captains discovered 'that the incoming tide propelled their ships from open sea to here.
'London Bridge stands where the river became narrow enough for Roman engineers to build their bridge.
'Through the centuries, the capital has grown westwards, 'away from the sea.
As London expanded, the river has been made narrower 'and so the tide moved further upstream.
'Odd as it seems, because the tide defines where the coast ends, 'even the Houses of Parliament are coastal.
'In fact, you have to go 17 miles, all the way up to Teddington lock, 'to officially find out where London's coast stops.
'That's only because of the lock gates.
'Without them, it would be tidal for miles and miles.
' So there we have it.
London-on-Sea.
Cheers.
All the way back down on the seaward side of London, the coastline becomes too low-lying and marshy for development.
The Thames was the original home of the Royal Navy.
For 400 years it was based here, defending the realm.
Our maritime supremacy was held together by an uncelebrated but essential ingredient of seafaring life.
It's when you see a ship sailing that you truly appreciate the significance of rope.
Chatham was one of Elizabeth I's original Royal Naval ports.
We've press ganged Alice Roberts to unravel the story of the humble rope.
In the days of sail, the Royal Navy relied on four main suppliers for its rope.
Portsmouth, Plymouth and Woolwich are now closed.
The only site still making rope is Chatham.
'In fact, Chatham's historic dockyard 'houses the last traditional working ropery anywhere in the world.
'If you want rope the old-fashioned way, this is the place to get it.
'Richard Holdsworth has worked at the dockyard for over 20 years.
'It's safe to say he's the man who knows the ropes.
' This is where it all goes on.
Welcome to the rope walk, Alice.
It's huge! How long is this building? It's 1,000 feet long.
When it was built, it was the longest brick building in Europe.
I can barely see the end of it.
It's a long way away.
The building is so long that the Rope makers have come up with a simple solution to getting from one end to the other.
'Riding their bikes is an art in itself.
' THEY LAUGH The bearings aren't too hot either! 'The room had to be so long because rope, for strength, is made in one continuous length.
' These are the bobbin banks, where the whole of the process starts.
The fibres are being spun into yarn.
Here, they pass through these wonderful colander things.
Everything is controlled by rope.
The machines are controlled by rope.
The signals are controlled by rope.
It's coming through there and it's coming out and turning into This is the forcing tube.
This is the register plate.
One of the skillful bits of the rope maker's art is how this is all threaded together.
The way these yarns come through, it's twisting at the same time.
They have to come together and lay together.
They're all lovely and parallel.
There's no gaps in there.
It's tight.
The construction is firm all the way through it.
This isn't a finished rope.
No.
This is strand.
This is the second part of rope making.
The yarns are the first.
The fibres are spun into yarn.
They're twisted to the right.
In the second stage, the strand, they're twisted to the left.
The third stage, it twists the other way.
That's really the secret why it doesn't unravel.
If you take it over to the next part side of the rope walk.
We put 6 strands onto 6 seperate hooks.
That's a vicious looking thing.
It's good fun, isn't it with all these wonderful hooks.
'Every rope is made to be 720 feet long.
'That's a standard length that the Navy required to anchor ships in 40 fathoms.
'The room's over 1,000 feet because as the rope is twisted together, it shortens.
' BELL RINGS And that's all going to happen.
MACHINE WHIRRS Each of these six strands of rope will be made into two ropes.
At the end, these three have been brought together to a single hook.
As it twists, it drives the top cart down the floor.
The rope that's being made is driving the cart.
There's no other mechanical force to it, apart from the twist of the rope The real rope maker uses a piece of rope wrapped around the finishing rope as a sort of a brake.
That controls the angle the rope comes together at.
It's a mechanised process but you need human skill.
That's right.
We need to squeeze in here to let Fred past.
So you see, there's New ropes! So the Royal Navy totally relied on the strength of these ropes made at places like Chatham.
They drove the ship.
Sailing ships are reliant on ropes for their mast for their sails.
It's not only the enemy that's the danger, it's the sea itself and winds Sailors are trusting their lives on these ropes.
Trusting their lives.
'The rope walk at Chatham survives because its rope is still in demand 'for the world's finest sailing ships 'and they even make tow ropes for the Army's tanks.
' Two new ropes.
There we have it.
The Thames has always provided London's life blood.
But it's also the capital's weak spot.
Enemies have used it to strike at the heart of the nation.
In the middle of the estuary lies Redsand Fort, anti-aircraft platforms designed to counter Luftwaffe raids.
They've survived the elements since 1941.
During World War II, the River Thames acted as a shining path for the Luftwaffe.
German aircraft flew upriver to attack London's docks.
The biggest raid was time to coincide with low tide so there'd be less water for firefighting.
In 11 months, they dropped 40,000 high explosives and millions of incendiary bombs.
It's estimated one in ten failed to explode.
They're still turning up today.
'Even now, the Royal Navy divers get called out three times a week to deal with unexploded bombs.
'Lieutenant Jason White is the officer in charge of the southeastern sector.
'Today, they've been called to Sheerness, 'not because of German bombs, but British anti-aircraft shells.
' These are what we're dealing with.
What are you doing? Don't get it out on my account! And these are four-inch shells.
These are the average standard things we get week in, week out.
How safe are these, if that's not a stupid question? They're live.
It's very dangerous.
We keep them cool in water, which they've been in for 60 years.
They've all been sucked up in a dredger.
They didn't go off in the first place.
So, you can Not 100% say, but the threat assessment's gone down.
You're happy that they're not about to go at a second's notice.
I'm not really really happy.
It's amazing that World War II's been over for 60 years but that cache there brings it back.
The sea bed's littered.
Land gets cleared.
It's in the public eye.
This stuff just sits there.
We use the sea all the time.
More people dive, there's fishing.
It's all going to turn up.
The safest way to deal with shells is a controlled explosion.
First, they're wrapped up with a block of plastic explosives.
Then, they're lowered into the water to dampen the explosive force.
We're going to light the fuse, a four-minute safety fuse.
One in each hand.
Three, two, one GoBurning.
Fuse is burning.
A small pop? Nearly took my hand off! 'We've only a matter of minutes to get clear.
'Then, it's an anxious wait.
' Brilliant! You get to do that how many times a day? Depends.
You've got nearly as good a job as me! 'The largest explosives the Navy usually deal with 'are German anti-shipping mines weighing in at over 1,000 kilos.
'But they're as nothing compared to the time bomb waiting off Sheerness.
'The USS Richard Montgomery is an American cargo ship 'wrecked in the heart of the Thames estuary.
'Her holds contain 1,400 tonnes of high explosives.
She's lay dormant here for over 60 years.
Where does the wreck sit? You've got Sheerness and the Isle of Sheppey.
That's where we sailed from.
We're heading up the Medway.
As we come up this channel, the wreck's just there.
You can see her masts sticking out the water.
She's always visible? There's always something of her sticking out the water.
Looking at the vessels, this is a busy place.
Hugely busy.
You've got the Thames that way and the Medway the other.
So it couldn't be in a more inconvenient spot? You could say that she ran aground in an interesting place.
I find that a sinister sight.
It seems so wrong that that's a ship lying dead but not properly disposed of.
Ships should be floating.
'The Montgomery packed with explosives survived U-boat attacks and safely crossed the Atlantic.
'When she entered Sheerness, a storm was gathering.
'Most of the crew went ashore and as the wind increased, those on watch were powerless to stop the ship 'drifting onto a sand bar.
'When the tide fell, the weight of munitions onboard broke the vessel in half.
' Now, she's in two pieces.
And she was fully laden With explosives.
All sorts of spectacular fireworks.
Lots of things that go bang.
'Stevedores unloaded the rear holds of the wreck, 'but the front still contains an array of corroding bombs.
' If you look at a 1,000lb bomb, their standard big bomb dropped from a heavy bomber, she's got thousands.
500lb bombs.
Thousands.
Small bombs.
Thousands.
If you leave them, they're fine.
They're in a nice environment, they are in cool water.
The water keeps them cool keeps them happy.
If stuff leeches out, the water washes it away.
There are more dangerous things on board.
Fuses that go in bombs to make them dangerous are in boxes somewhere.
Cluster bombs which were loaded with fuses inside them.
'Because of the difficulty in clearing the wreck, it's been left where it sank.
'It isn't the Navy's responsiblilty but the Department of Transport.
'They regularly check it.
So far, the explosives have remained stable.
'But surveys of the hull indicate that it may break up in the next nine years.
' .
.
widening of the crack here.
The crack changes direction, going down into the sea bed.
As you can see here, this is one of the sonar images of it.
This area around it has been dug out by the tide.
Any explosives that fall out will sit in this dip.
It's in its own crater? Pretty much.
That's the effect of the tide washing past it.
'It's hoped that the crater will contain explosives spilling out.
' If it was to go boom, how big a boom would it be? Big big bang.
'It's a big IF, but if the worst were to happen '.
.
the explosion would equal the force of a small atomic bomb.
'Government experts estimate that the blast would throw debris 3,000 metres into the air.
'A subterranean shockwave could damage buildings up to 3km inland.
'The seismic jolt would be measurable around the globe.
'No-one's sure what to do.
It's a dilemma.
'Leave the ship to break up, try to dismantle her 'or risk a controlled explosion? 'Whatever the answer, doing nothing may soon not be an option.
'East of Sheerness lies the Isle of Sheppey, 'and the first higher ground of my journey 'it doesn't last long before dropping down to the Swale, 'famous for its oyster beds.
'As well as being renowned for shellfish, 'Whitstable is an unlikely landmark in the development of modern diving.
'The world's first diving helmet was invented here in the early 1820s.
'Jim Hutchison is in his 80s, 'a lifelong diver who's keeping the traditions alive.
' This helmet weighs approximately 45 pounds.
Made just at the end of World War II.
I prefer to use this type of gear all the time.
'I've recovered crashed aircraft.
'I've dived in shafts and tunnels.
'You're carrying, without your own bodyweight, '186 pounds of weight.
'Once you're in the water and you get to the bottom, 'it's just like moon walking.
'It's a wonderful feeling.
'I've had several narrow escapes - a 16-tonne trailer dropped on me.
'You've got to have a certain nerve.
'It's no good getting in a panic.
'That's the worst thing that can happen.
'Some places around the British coast 'there's hardly any visibility at all.
'I found a ring worth 500 once that a lady had dropped.
'This type of equipment is part of history.
Children love to see it.
'On several occasions, I've had ladies come up to me 'and say, "Is that a robot in there?" 'I just love to do it.
I'm reluctant to give it up.
' When they put me in my box, they'll bury me in a suit! 'I'm now approaching the end of my journey.
'Beyond the quintessentially English resort of Margate 'there's time for one last stop.
' Out there lie the Goodwin Sands, known to mariners as the Widow Maker.
'That's because these notorious sandbars 'contain the world's largest concentration of shipwrecks.
'A cross-section of British maritime history is buried beneath them.
' This is the most unexpected place I've ever arrived at.
If you stand, you just start to disappear into it.
It's easy to understand why they called it the ship swallower.
'The sands are completely submerged at high tide.
'But for a couple of hours each day, they're an island off our island.
' MUSIC: THEME TO CRICKET COVERAGE 'We've come here to commemorate an eccentric local tradition.
'Until recently, an annual game of cricket was played here.
'The reason why has been washed away by the sands of time.
' You've got to go to the coast to find a Scotsman playing cricket! 'Maybe the reason they stopped playing cricket on the sands 'is that it's so easy to get caught out by the rising tide.
'That's what happened to us.
'After our filming, we were stranded and had to be rescued by the RNLI.
'It goes to show, we should never underestimate the power of the sea.
'We've completed some extraordinary journeys around the British Isles.
'All in all, tt's been quite an adventure.
' Don't look down! 'And, you know, for me, the best bit about the coastline, 'is that it belongs to all of us, ours to share.
'
There might be nothing here today except majestic emptiness as the Romans hadn't liked it so much they established a trading post and called itLondinium.
I'm going to discover how that moment in hsitory defined England's capital coast.
And to help make sense of it all, we've our usual team.
Nick Crane goes in search of a mighty river and its violent inhabitants.
I don't believe it! Mark Horton seeks out where London's coast ends and the Thames begins.
Alice Roberts gets hands-on experience of one of Britain's first jobs, making salt.
Miranda Krestovnikoff has a close encounter with the remarkable thornback ray.
Watch the thorns, right! I'm going to discover the story of an abandoned time bomb, big enough to rock the entire Thames estuary.
This, of course, is Coast.
The latest leg of our journey takes us from Felixstowe in Suffolk to Margate in Kent.
And there's a little diversion to London.
This stretch of coast has seen repeated waves of tribal settlers that have helped forge our national identity.
Saxons, Jutes, Vikings, Danes.
They all came here, you know.
They were so impressed, they all decided to stay.
But our ancestors never got round to colonising this headland.
Until recently, it was mostly a marsh, but now, it's Felixstowe.
The UK's largest container port.
I'm going to see what one of those is all about.
95 per cent of the goods we consume on our island arrive here by sea.
So when you're shopping, it's odds on that you're buying stuff that came here by ship in boxes like these.
In all, 40 per cent of Britain's trade comes through this port.
Much of that trade once flowed through London, but it moved here because Felixstowe can take bigger ships.
These containers come from every corner of the world.
There are about 6,000 of them on that ship alone.
On the biggest vessels, there are up to 10,000 containers.
Each crane must unload a box every minute, day and night.
Felixstowe handles nearly two million containers per year.
Some of the contents aren't always what they appear.
Stopping smugglers using any one of these incoming box is a Herculean task.
How on earth do they do it? Hi, Kevin.
'Kevin Sayer is one of the few people with the power to open any box.
'Our first container has come from Africa.
'It's suspicious, but they won't say why.
' Is that typical? It looks so completely harmless.
That's what the criminals and the smugglers are trading on.
They want their consignment to look as legitimate as possible.
So it evades our controls.
It does seem a bit odd that it's only half full.
Kevin Do you want to have a look at this? Is there something inside? The X-ray shows a dark block in the image.
It's a black bin liner, Kevin.
It's coming out.
It sounds heavy.
Made a thud there.
Maybe it's the latest Wilbur Smith! Bin liner within a bin liner.
That even looks suspicious to me! This looks like cannabis resin.
That looks like cannabis! Look at that! I can't believe it.
You've set this up just for me.
I wish we could have arranged it.
Is the whole cargo now officially dodgy? Yeah, the whole cargo will effectively be forfeit.
We use a historic phrase "forfeit to the Crown".
What's the Queen going to do with that? It becomes her property.
I'm going away from this with the skewed idea this stuff's popping out of every case.
It's so easy(!) It turned out that our very first container actually had cocaine in it.
Street value, 80,000 pounds.
And that's just a drop in the ocean.
Last year, Customs seized 4.
9 tonnes of the stuff at our frontiers.
Felixstowe port thrives because of the estuary's deep water.
Generally, along this coast, the sea is incredibly shallow and the marshland just merges into it.
All this glorious mud means that it's a haven for wildlife.
Some of it's surprisingly big.
These mud flats are known as saltings, home to an unusual seal colony.
Beneath the layer of fresh grey mud, they've turned a curious reddish colour.
Seals.
Rare common seals.
They're not common to me! No! Oh, yes! Beautiful, eh? 'Tony Haggis is a local guide to these quiet backwaters.
'He visits them daily.
' One of them has a strawberry blonde head and strawberry blonde flippers! What's that about? They go different colours.
Mainly red.
The oxidisation from the saltings turns their coats a rusty colour.
The mud they're on dyes their fur! Where else does that happen? Only in the Thames estuary, I think.
Where we have salt marshes.
These are unique? Yes.
The iron oxides naturally found in the mud stains the seals' coats.
After just two weeks, the young are turned ginger.
Are they reliant on their mothers? They have to suckle from Mum.
They can it do in or out the water.
She has very rich milk.
Within two weeks, the pups put on twice their weight.
All of a sudden, she chucks the pup out to fend for itself then goes and mates for next year.
So what happens? Does she wake up and it's no more Mrs Nice Guy? Sometimes, when the pups have been chucked out, you hear the pups crying and it gets your heart strings.
Nothing we can do.
It's nature.
They have to take care themselves.
Oh, it's terrible! She doesn't want to know any more.
The seal colony is protected from the sea by the headland at Walton on the Naze.
It's on the geological map because of erosion.
The high rate of wear and tear reveals a unique glimpse into our distant past.
Nick Crane likes a little time travel.
There are few places where the coastline changes as quickly and as dramatically as the southeast.
These pillboxes were built in 1940, when this was a clifftop.
60 years of erosion dropped that pillbox onto the beach.
But as well as destroying our more recent history, it's also revealing our ancient past.
Rapid erosion makes Walton one of the finest sites for fossils in Britain.
Gerald Lucy has collected fossils here since he was a boy.
And his finds have taught him how to read the story of this landscape This is London clay, which used to be a mud under the sub-tropical sea.
These are the oldest rocks in the Naze's cliffs.
The rocks get younger as you go up.
If we move up here, I'll show you more.
'Climbing the rock strata at Walton is a remarkable journey through time.
Have you ever found any amazing fossils here? I think the best fossils sometimes are the smallest.
My favourite are sharks' teeth, which you can find on the beach quite easily.
Sharks' teeth fascinate me because they are so common as fossils and they are so exquisitely preserved.
Razor sharp.
And they are 50 million years old.
The sort of thing anybody can find.
This creature is by far not the largest of the teeth you find.
This one here What?! .
.
I have in my pocket! I don't believe it! This is from the creature known as megalodon - Carcharodon megalodon is its Latin name If you make a model of the jaws, and put these teeth in, then you can step into its mouth standing up! You would not want one in your bath! No! Megalodon means "big tooth", they were the largest predator fish ever to swim the sea.
Their fossilised teeth are all that's left.
The super predator was up to 60 feet long.
Studies of whale bones reveal that they featured on a megalodon's menu.
'All that was 1.
5 million years ago.
'Megalodon died out because the waters of Essex became too cold.
'As we climb, the finds become more recent.
' Here is the sandy deposit which is laid down just before the Ice Age, and it's full of fossil shells.
A lot will be found on the beach.
A left-handed whelk.
These shells, some of them are Mediterranean species, and some of them are Arctic species.
As you move up the cliff, the Mediterranean species get fewer and the Arctic species become more common.
It's a definite indication of global cooling as we approach the Ice Age.
'Our journey through time is about to get a little more tricky.
'Walton's cliffs are notoriously unstable so we roped in the Coastguard's expertise.
' Off we go.
All in a day's work! 'The final half yard of cliff was formed in the last 500,000 years.
' What have we got here, Gerald? What we've got here is a layer of gravel.
It's completely different.
This gravel is clearly a river gravel.
It consists pebbles aren't rounded at all.
It's not a beach gravel, it's not marine deposit, so it was a river, a very large river, because the same type of gravel is across much of north Essex and Suffolk.
'Recent studies of these river gravels show that large parts of Essex 'were covered by a vast torrent that dragged rocks here from as far away as north Wales.
'To appreciate the sheer scale of this ancient river 'we need to get some perspective.
' Now there is a huge river, it went right the way across here.
It was much larger than we could imagine.
Amazing! A graded river, many channels, and it was the Thames.
The Thames? How astonishing! What we now call the Thames used to drain from the Welsh mountains, flowing across the country to late join the Rhine in the marshland that is now the North Sea.
But 600,000 years ago, the river's course was blocked by the southerly limit of a vast ice sheet.
When it melted, the Thames burst through a weak spot to find its new path.
If it hadn't been for the ice sheet, the Thames would have been here, London would have been in Essex.
London would have been at Walton on the Naze.
It's amazing what you can discover from a stroll along the beach.
Crowded along this sandy shore are towns that grew up to serve holiday-makers from the capital.
Chief among them is Clacton.
This genteel little town was invented in 1864 as a pleasure beach for well-to-do Londoners.
The introduction of bank holidays and the arrival of the railway opened up Clacton to all-comers.
The town boomed.
MUSIC: "All Day And All Of The Night" by The Kinks By the 1960s, a new breed of Londoner had arrived on the coast.
And they came like this! What a fantastic way to travel by the sea I don't know why I've only had a car driving licence all these years! I want to be a mod as well! But the fun came to a grinding halt on the Easter bank holiday 1964, It was the wettest weekend for 80 years.
There was tension between rival gangs of mods and rockers, two tribes that were about to become infamous.
'The machine they use marks their faith.
For the mods, it's a scooter.
'In the rain, they cover up their elegant clothing.
'Their rivals, the rockers, look the same in any weather: a black uniform for all seasons.
'A rocker needs a motorbike can to a ton to a scooter's 50.
'The difference in power is a matter of masculine pride.
' 'Masculine pride led to fighting.
'The police struggled to keep the peace and the ational press had a front page sensation.
' Scooter gangs 'beat up' Clacton A desperate SOS went out from police "as leather jacketed youths and girls attacked people in the streets, turned over park cars "broke into beach huts, smashed windows and fought with rival gangs.
" Despite the lurid headlines, only 12 youths were prosecuted.
The damage was estimated at 243 pounds.
The true cost was the town's reputation.
Holiday-makers cancelled summer bookings and Clacton nose-dived.
And the mods and rockers? Though the media lost interest, they went on to have punch-ups at the seaside for years to come.
Just south of Clacton is the driest place in the UK.
It gets just over 50 centimetres of rain per year.
By some definition, it's almost a desert.
Combined with all this sea water, it's a perfect place to make salt.
Maldon is famous for the sea salt it produces.
Beloved of celebrity chefs and exported around the world.
A traditional salt factory is the last surviving remnant of a once-thriving enterprise that dates back to pre-Roman times.
Alice Roberts is somewhere on the Black Water estuary, looking for the evidence of our eldest industries The place names in this area show the importance of salt.
We've got Salcott, Gore Saltings.
When the entire British Isles is surrounded by salty sea why is salt so important to this bit of the coast? 'This estuary was once the centre of the country's salt production.
'Mark Atkinson is a local field archeologist who has studied the remains of this industry.
'These banks may look natural, but they're not.
'They are nown as red hills, they're made up of 2,000-year-old remnants of countless terracotta vessels.
' If we look closely, what we have here is an eroding section into a mound of red material.
You can see here we've got estuarine clays on top.
But, from here downwards, a very red soil.
And you can see here, baked clay.
Charcoal here.
Even some Roman pottery here.
Yeah! It's a large area that they were doing this salt-making process over.
This particular red hill is about 100 metres across.
Salt-making, even in the Roman period, was a complex, big and labour-intensive job.
'These pieces of terracotta and the charcoal evidence of fires reveal the importance of this coast to the Romans.
'On a small scale, Mark is recreating this basic industrial method.
'The sun was used to evaporate sea water into concentrated brine.
'This was boiled until salt crystals started to appear on the surface.
'The value of salt to Roman society is still with us.
' There's evidence in the English language that it was prized substance.
We get "salary" from the payment in salt from the Latin for salt.
"Salary.
" Yeah.
And if someone's making a valuable contribution, they're worth their salt.
Yeah! Why was it a precious commodity? Well, essentially, rather than as a condiment, really as a preservative.
Salt was the only means of keeping food fresh or preserved for any prolonged period of time.
So there was this huge industry producing sea salt here.
Why isn't it here any more? I think because it was too time-consuming.
And that the discovery and exploitation of inland salt showed people that this was no longer a good use of their time.
Mining of rock salt takes over from getting sea salt from estuaries like this.
Yeah.
I have to say, with our miniature briquetage evaporation tank, we've made quite a lot of salt.
It's impressive.
It shows that it was an effective industry of its day.
Definitely.
I shall be taking that home for my tea! Across the estuary, at Sale's Point, there's another bounty from the briney deep - This is Bradwell Cockle Spit and it lives up to its name.
' Look, there's one.
There's another one.
In fact, it's nothing but them here.
Millions, gazillions of cockleshells.
The beach is made of them, all be washed here by a confluence of the tide.
'The Cockle Spit is the most northern point of the Dengie marshes, 'a vast sparsely inhabited landscape that's been reclaimed from the sea.
'Surprisingly, these shallow waters off the southeast coast 'are the breeding ground of a wonderfully exotic bottom feeder.
' 'The Thames estuary is home to more than 100 species of fish.
'I'm on the hunt for one with cunning camouflage and vicious armour.
'The thornback ray looks exotic but actually lives within commuting distance of London.
'It's a species that we know very little about.
And there are concerns that thornback rays are in decline.
'I've joined Ewan Hunter, a fisheries expert from Cefas, 'to help with their latest tagging project.
'They're working alongside the fishing industry to find out more about these prettily characters.
But before we get started, we need a freshly caught thornback ray, These are actually the most commonly landed species of ray in the North Sea.
'It's quite likely to have landed on your dinner table at some point.
It's usually sold as skate.
' Ewan, we've got one super live ray for you.
Beautiful.
Can I lift her out? Just be careful with your fingers.
There's a mouth under there.
I'm a real amateur at this! Ooh! Bloody hell! Sorry.
Just watch the tail.
Watch the thorns, right? OK.
Pull her out.
That went right through my glove! Unbelievable.
Sorry, I'll let you handle that.
We're just gonna take two measurements.
We'll start off measure her total length, nose to tail.
Now, this lady is 62 centimetres long.
We'll take a measurement across the wings.
44 centimetres across.
Our biggest females are more than a metre long.
They are a big fish.
Now just taking a look at her, you can see there is Well, I felt them.
Those really ferocious thorns down the back.
They're curved over.
Great defence.
When she's angry, she'll thrash her tail around.
You really have to be careful.
There'd be a lot of blood everywhere! Can we flip her over and look at the underside? Let's just get hold of her here.
Ah, beautiful! Look at the mouth! Can I just feel that? Rows of teeth.
Yeah, rows of teeth! Because they're bottom feeders, so their mouth is on the under side.
Yes.
I'm going to tag her with one of these devices.
That's tiny.
What sort of information does this tag give you? The tag will record depth and temperature every five minutes for about one year.
We can work out where the fish has been between release and recapture with the date from the tag.
Instead of staying in one place, the fish move three times further than we suspected previously.
So instead of staying put the fish are migrating into the Thames during the spring when the fish lay their eggs.
During winter, the fish move right out into the wider southern North Sea, where they tend not to be caught, And this is a migration we were totally unaware of previously.
If you'd not used these tags, you'd never have found out.
No.
It's all new stuff.
'The external yellow marker makes tagged rays easy to spot 'amongst fishermen's catch.
'The surprising migrations revealed by the project will help us conserve the stocks of rays off our coast.
' Is she ready for release? Yes.
I'll let you do the honours.
Come on, girl.
OK.
Back in the water.
There she goes.
We know that the Thames estuary is an important area for these fish.
This tagging project is vital to ensure the thornback rays have a future off our coastline.
So far, I've been travelling south along this eastern coast.
At Southend, I hang a right.
Up there's London, and who can resist that? But, before you get to the big city, you've got to get past its big mess.
London's rubbish gets shipped downstream to Mucking marsh.
Its popularity in Saxon times makes it an archeological treasure trove, as well as one of the UK's largest landfill sites.
It's Lucy Mancer's job to keep on top of it.
It's a nice place to work.
It's hostile, in terms of the environment, but it's a nice PLACE, in terms of people and things to do.
It is a big site here.
It's well over 300 hectares in size.
We take a fifth of London's waste.
Each of our containers takes 12 to 14 tonnes of compacted waste.
We get 20 to 30 containers on a barge, ten barges a day.
'Working here can be very dusty, a bit dirty and occasionally smelly, 'depending on where you work and what we're emptying at the time.
'I don't think my friends and family know the full extent of what I do.
'They know I work in a landfill site 'but they haven't seen the scale of it or the machinery we work with.
' If somebody came back and did an archeological dig, I hope that they would be surprised at the things we throw away, that they would be surprised at the number of carrier bags, as I am.
I'm sure they'd find it interesting, it would tell them about the way we live today.
Just around the river bend is Tilbury.
From here the whole coastline becomes a manmade construction.
Buried beneath are successive layers of our past.
I'm after one event in particular.
It's one of the most legendary moments in all of English history.
On 8th August 1588, Queen Elizabeth I came to Tilbury to rally her troops.
20,000 men, London's last line of defence against the Spanish Armada.
This is it! This is THE Tudor jetty.
Queen Elizabeth I stepped ashore here.
The day is long gone, but the stones that she walked upon when the threat of Spanish invasion was very real are still here.
The speech the Queen made that day is often seen as the defining moment of her reign.
"I know that I have the weak and feeble body of a woman, "but I have the heart and stomach of a King of England.
"And I think foul scorn of Parma or Spain or any prince of Europe "who dares to invade the borders of my realm.
" Nobody speaks like that any more! Travelling the 12 miles upstream from Tilbury into London it's impossible to ignore the ever narrowing estuary.
Where exactly does the coast stop and the river begin? Mark Horton's looking into a tidal conundrum.
When the Ordnance Survey had to define what counted as coast their simple solution was to include everywhere that had a tidal range.
How far does the tide actually extend up the Thames? Is London on the coast? 'I'm going to find that defining point, 'to go where technically the coast stops - it's a journey back through London's maritime history.
'These docks helped make London the greatest port in the world.
'The Royal Albert dock was built in 1874 to be the biggest in Britain.
'This vast complex was necessary to trap the tidal water of the Thames 'and accommodate bigger ships.
'Terry Bowden worked his entire life in the Port of London 'starting in 1938.
'He's the last of a family of river men, stretching back 150 years.
' Are you sad to come back and see this as a leisure place, an airport? I'm sick! I've got a big lump in my throat.
Straight.
It knocks the life out of you when you see it like this.
I loved every minute of it.
We always used to say it was more of a life than a living.
'This massive lock was one of just two ways out into the Thames.
'The vast lock gates trapped the water, as the river dropped 6.
5 metres at low tide.
'For Terry, 'the lock's a reminder of a lifetime spent as a lighterman, 'a skilled occupation, licenced to drive bargeloads of goods around the docks in the river.
'It's an ancient profession that's almost completely redundant.
' You can see over there how low the tide is.
That's right.
Three big wharves there they've flattened, all gone.
Awful.
One of them we called the stinker wharf.
They made bones.
It used to pen and ink when you went by there.
'When Britain ruled the waves, it also made the rules.
'We're crossing from the eastern into the western hemisphere.
'Greenwich Observatory marks the line separating east from west.
'The meridian is here because, when English navigators charted the world 'they decided that Greenwich was the centre of the maritime universe.
' Is that Deptford? That is Deptford.
That's where they hung the pirates up in chains.
Yeah.
That leads up to Leeds Castle where old Henry VIII used to chop the oak trees down, throw them out there up to the Royal Naval Dockyard where they built the ships that defeated the Spanish Armada in the good old days! There's a few docks, mostly filled in.
Oh, yeah.
You've still got Deadman's Dock just there.
When they was digging the docks out, they found all the bodies from the Great Plague buried there, so they call it Deadman's Dock.
Right alongside they built them blocks of flats.
No good living there if you're superstitious! 'Tower Bridge used to stand in the middle of a thronging dock, known as the Pool of London.
'Amazingly, this is also where London has its very own beach.
' 'It was created in the 1930s for the working classes by dumping sand on the foreshore.
'Martha Snooks and Ted Lewis 'remember coming to the beach as a special treat.
' I'm amazed.
You come down here and there's beach sand.
It's not like it used to be.
Sand covered right the way down.
All the way along.
Now, it don't seem true, but it was true.
My dad and granddad were dockers.
That's the family I come from, tough old family.
We never had nothing.
We thought it was the seaside.
Mum told us it was the seaside.
She really believed it herself, that it was the seaside.
Mum used to knit us little costumes out of wool.
They was terrible.
They made you itch.
When you got in the water they used to fall down and end up around your ankles.
Only little children.
Embarrassing! But you must have had barges and warehouses here, Ted.
The river was very busy.
Boats coming up and down, unloading.
Barges.
It was a very busy river.
They must have sat on this beach and looked out watching the boats going out to foreign countries.
That was exciting for us.
We'd go home with a windmill.
Or Mum would buy us a paper umbrella.
We'd put them up and think what a lovely day we'd had.
Oh, I do like to be beside the seaside 'So, if London had a beach, does that make it coastal? 'Time and tide wait for no man, so onwards and backwards, 'to London's very beginning.
' James, can you stop the engines? ENGINES STOP Just feel the tide.
This is the reason why London is here.
This great tideway that brought the ships in, and why the Romans chose this spot as their capital.
'2,000 years ago, Roman sea captains discovered 'that the incoming tide propelled their ships from open sea to here.
'London Bridge stands where the river became narrow enough for Roman engineers to build their bridge.
'Through the centuries, the capital has grown westwards, 'away from the sea.
As London expanded, the river has been made narrower 'and so the tide moved further upstream.
'Odd as it seems, because the tide defines where the coast ends, 'even the Houses of Parliament are coastal.
'In fact, you have to go 17 miles, all the way up to Teddington lock, 'to officially find out where London's coast stops.
'That's only because of the lock gates.
'Without them, it would be tidal for miles and miles.
' So there we have it.
London-on-Sea.
Cheers.
All the way back down on the seaward side of London, the coastline becomes too low-lying and marshy for development.
The Thames was the original home of the Royal Navy.
For 400 years it was based here, defending the realm.
Our maritime supremacy was held together by an uncelebrated but essential ingredient of seafaring life.
It's when you see a ship sailing that you truly appreciate the significance of rope.
Chatham was one of Elizabeth I's original Royal Naval ports.
We've press ganged Alice Roberts to unravel the story of the humble rope.
In the days of sail, the Royal Navy relied on four main suppliers for its rope.
Portsmouth, Plymouth and Woolwich are now closed.
The only site still making rope is Chatham.
'In fact, Chatham's historic dockyard 'houses the last traditional working ropery anywhere in the world.
'If you want rope the old-fashioned way, this is the place to get it.
'Richard Holdsworth has worked at the dockyard for over 20 years.
'It's safe to say he's the man who knows the ropes.
' This is where it all goes on.
Welcome to the rope walk, Alice.
It's huge! How long is this building? It's 1,000 feet long.
When it was built, it was the longest brick building in Europe.
I can barely see the end of it.
It's a long way away.
The building is so long that the Rope makers have come up with a simple solution to getting from one end to the other.
'Riding their bikes is an art in itself.
' THEY LAUGH The bearings aren't too hot either! 'The room had to be so long because rope, for strength, is made in one continuous length.
' These are the bobbin banks, where the whole of the process starts.
The fibres are being spun into yarn.
Here, they pass through these wonderful colander things.
Everything is controlled by rope.
The machines are controlled by rope.
The signals are controlled by rope.
It's coming through there and it's coming out and turning into This is the forcing tube.
This is the register plate.
One of the skillful bits of the rope maker's art is how this is all threaded together.
The way these yarns come through, it's twisting at the same time.
They have to come together and lay together.
They're all lovely and parallel.
There's no gaps in there.
It's tight.
The construction is firm all the way through it.
This isn't a finished rope.
No.
This is strand.
This is the second part of rope making.
The yarns are the first.
The fibres are spun into yarn.
They're twisted to the right.
In the second stage, the strand, they're twisted to the left.
The third stage, it twists the other way.
That's really the secret why it doesn't unravel.
If you take it over to the next part side of the rope walk.
We put 6 strands onto 6 seperate hooks.
That's a vicious looking thing.
It's good fun, isn't it with all these wonderful hooks.
'Every rope is made to be 720 feet long.
'That's a standard length that the Navy required to anchor ships in 40 fathoms.
'The room's over 1,000 feet because as the rope is twisted together, it shortens.
' BELL RINGS And that's all going to happen.
MACHINE WHIRRS Each of these six strands of rope will be made into two ropes.
At the end, these three have been brought together to a single hook.
As it twists, it drives the top cart down the floor.
The rope that's being made is driving the cart.
There's no other mechanical force to it, apart from the twist of the rope The real rope maker uses a piece of rope wrapped around the finishing rope as a sort of a brake.
That controls the angle the rope comes together at.
It's a mechanised process but you need human skill.
That's right.
We need to squeeze in here to let Fred past.
So you see, there's New ropes! So the Royal Navy totally relied on the strength of these ropes made at places like Chatham.
They drove the ship.
Sailing ships are reliant on ropes for their mast for their sails.
It's not only the enemy that's the danger, it's the sea itself and winds Sailors are trusting their lives on these ropes.
Trusting their lives.
'The rope walk at Chatham survives because its rope is still in demand 'for the world's finest sailing ships 'and they even make tow ropes for the Army's tanks.
' Two new ropes.
There we have it.
The Thames has always provided London's life blood.
But it's also the capital's weak spot.
Enemies have used it to strike at the heart of the nation.
In the middle of the estuary lies Redsand Fort, anti-aircraft platforms designed to counter Luftwaffe raids.
They've survived the elements since 1941.
During World War II, the River Thames acted as a shining path for the Luftwaffe.
German aircraft flew upriver to attack London's docks.
The biggest raid was time to coincide with low tide so there'd be less water for firefighting.
In 11 months, they dropped 40,000 high explosives and millions of incendiary bombs.
It's estimated one in ten failed to explode.
They're still turning up today.
'Even now, the Royal Navy divers get called out three times a week to deal with unexploded bombs.
'Lieutenant Jason White is the officer in charge of the southeastern sector.
'Today, they've been called to Sheerness, 'not because of German bombs, but British anti-aircraft shells.
' These are what we're dealing with.
What are you doing? Don't get it out on my account! And these are four-inch shells.
These are the average standard things we get week in, week out.
How safe are these, if that's not a stupid question? They're live.
It's very dangerous.
We keep them cool in water, which they've been in for 60 years.
They've all been sucked up in a dredger.
They didn't go off in the first place.
So, you can Not 100% say, but the threat assessment's gone down.
You're happy that they're not about to go at a second's notice.
I'm not really really happy.
It's amazing that World War II's been over for 60 years but that cache there brings it back.
The sea bed's littered.
Land gets cleared.
It's in the public eye.
This stuff just sits there.
We use the sea all the time.
More people dive, there's fishing.
It's all going to turn up.
The safest way to deal with shells is a controlled explosion.
First, they're wrapped up with a block of plastic explosives.
Then, they're lowered into the water to dampen the explosive force.
We're going to light the fuse, a four-minute safety fuse.
One in each hand.
Three, two, one GoBurning.
Fuse is burning.
A small pop? Nearly took my hand off! 'We've only a matter of minutes to get clear.
'Then, it's an anxious wait.
' Brilliant! You get to do that how many times a day? Depends.
You've got nearly as good a job as me! 'The largest explosives the Navy usually deal with 'are German anti-shipping mines weighing in at over 1,000 kilos.
'But they're as nothing compared to the time bomb waiting off Sheerness.
'The USS Richard Montgomery is an American cargo ship 'wrecked in the heart of the Thames estuary.
'Her holds contain 1,400 tonnes of high explosives.
She's lay dormant here for over 60 years.
Where does the wreck sit? You've got Sheerness and the Isle of Sheppey.
That's where we sailed from.
We're heading up the Medway.
As we come up this channel, the wreck's just there.
You can see her masts sticking out the water.
She's always visible? There's always something of her sticking out the water.
Looking at the vessels, this is a busy place.
Hugely busy.
You've got the Thames that way and the Medway the other.
So it couldn't be in a more inconvenient spot? You could say that she ran aground in an interesting place.
I find that a sinister sight.
It seems so wrong that that's a ship lying dead but not properly disposed of.
Ships should be floating.
'The Montgomery packed with explosives survived U-boat attacks and safely crossed the Atlantic.
'When she entered Sheerness, a storm was gathering.
'Most of the crew went ashore and as the wind increased, those on watch were powerless to stop the ship 'drifting onto a sand bar.
'When the tide fell, the weight of munitions onboard broke the vessel in half.
' Now, she's in two pieces.
And she was fully laden With explosives.
All sorts of spectacular fireworks.
Lots of things that go bang.
'Stevedores unloaded the rear holds of the wreck, 'but the front still contains an array of corroding bombs.
' If you look at a 1,000lb bomb, their standard big bomb dropped from a heavy bomber, she's got thousands.
500lb bombs.
Thousands.
Small bombs.
Thousands.
If you leave them, they're fine.
They're in a nice environment, they are in cool water.
The water keeps them cool keeps them happy.
If stuff leeches out, the water washes it away.
There are more dangerous things on board.
Fuses that go in bombs to make them dangerous are in boxes somewhere.
Cluster bombs which were loaded with fuses inside them.
'Because of the difficulty in clearing the wreck, it's been left where it sank.
'It isn't the Navy's responsiblilty but the Department of Transport.
'They regularly check it.
So far, the explosives have remained stable.
'But surveys of the hull indicate that it may break up in the next nine years.
' .
.
widening of the crack here.
The crack changes direction, going down into the sea bed.
As you can see here, this is one of the sonar images of it.
This area around it has been dug out by the tide.
Any explosives that fall out will sit in this dip.
It's in its own crater? Pretty much.
That's the effect of the tide washing past it.
'It's hoped that the crater will contain explosives spilling out.
' If it was to go boom, how big a boom would it be? Big big bang.
'It's a big IF, but if the worst were to happen '.
.
the explosion would equal the force of a small atomic bomb.
'Government experts estimate that the blast would throw debris 3,000 metres into the air.
'A subterranean shockwave could damage buildings up to 3km inland.
'The seismic jolt would be measurable around the globe.
'No-one's sure what to do.
It's a dilemma.
'Leave the ship to break up, try to dismantle her 'or risk a controlled explosion? 'Whatever the answer, doing nothing may soon not be an option.
'East of Sheerness lies the Isle of Sheppey, 'and the first higher ground of my journey 'it doesn't last long before dropping down to the Swale, 'famous for its oyster beds.
'As well as being renowned for shellfish, 'Whitstable is an unlikely landmark in the development of modern diving.
'The world's first diving helmet was invented here in the early 1820s.
'Jim Hutchison is in his 80s, 'a lifelong diver who's keeping the traditions alive.
' This helmet weighs approximately 45 pounds.
Made just at the end of World War II.
I prefer to use this type of gear all the time.
'I've recovered crashed aircraft.
'I've dived in shafts and tunnels.
'You're carrying, without your own bodyweight, '186 pounds of weight.
'Once you're in the water and you get to the bottom, 'it's just like moon walking.
'It's a wonderful feeling.
'I've had several narrow escapes - a 16-tonne trailer dropped on me.
'You've got to have a certain nerve.
'It's no good getting in a panic.
'That's the worst thing that can happen.
'Some places around the British coast 'there's hardly any visibility at all.
'I found a ring worth 500 once that a lady had dropped.
'This type of equipment is part of history.
Children love to see it.
'On several occasions, I've had ladies come up to me 'and say, "Is that a robot in there?" 'I just love to do it.
I'm reluctant to give it up.
' When they put me in my box, they'll bury me in a suit! 'I'm now approaching the end of my journey.
'Beyond the quintessentially English resort of Margate 'there's time for one last stop.
' Out there lie the Goodwin Sands, known to mariners as the Widow Maker.
'That's because these notorious sandbars 'contain the world's largest concentration of shipwrecks.
'A cross-section of British maritime history is buried beneath them.
' This is the most unexpected place I've ever arrived at.
If you stand, you just start to disappear into it.
It's easy to understand why they called it the ship swallower.
'The sands are completely submerged at high tide.
'But for a couple of hours each day, they're an island off our island.
' MUSIC: THEME TO CRICKET COVERAGE 'We've come here to commemorate an eccentric local tradition.
'Until recently, an annual game of cricket was played here.
'The reason why has been washed away by the sands of time.
' You've got to go to the coast to find a Scotsman playing cricket! 'Maybe the reason they stopped playing cricket on the sands 'is that it's so easy to get caught out by the rising tide.
'That's what happened to us.
'After our filming, we were stranded and had to be rescued by the RNLI.
'It goes to show, we should never underestimate the power of the sea.
'We've completed some extraordinary journeys around the British Isles.
'All in all, tt's been quite an adventure.
' Don't look down! 'And, you know, for me, the best bit about the coastline, 'is that it belongs to all of us, ours to share.
'