26/10/2006 Coast

'The question is, why here?'

'I've dived all over the world, but it's easy to forget

'there are stunning wildlife dives closer to home.

'But when two local divers, Robert Walker and Paul Parsons, told me there was

'a good chance of photographing cuttlefish just offshore here, I was a bit sceptical.'

So are we expecting to see activity like this if we dive today, or is this quite unique?

I think we will find some cuttles. I don't know whether we'll quite get

this activity, cos everything's got to be just right for it,

but we should be able to find you some cuttlefish, and hopefully mating.

All this equipment and all this effort, I really hope it's worth it and there are cuttlefish down there.

Oh, look! There's a cuttlefish!

Exactly what we wanted to see.

They're such exotic-looking creatures.

You'd never imagine to find something like this right here in British waters.

It's very big. A couple of feet long.

Cuttlefish are in the same family as squid and octopus.

Sometimes known as the chameleon of the sea,

they can change their body colour and patterning

to mesmerise their prey.

Oh, gosh! What's he got? Oh, my goodness, he's just grabbed a crab!

That's amazing.

Don't think I've seen that before!

'Cuttlefish have a sharp parrot-like beak and a venomous bite, which will make short work of this crab.'

'As the sea warms in spring, cuttlefish invade these shallow waters to mate and lay their eggs.

'This part of the south coast is a real hot spot for them.

'Male cuttlefish dazzle the smaller females with their striped patterns and flowing tentacles.'

'They mate head to head, with tentacles entwined.'

'After mating, the male cuttlefish guards his female as she deposits

'her eggs, dyed black with ink to deter predators.'

'This cuttlefish invasion lasts all summer, but, as the water cools,

'and with their life cycle complete,

'both males and females die,

'leaving their bones to be washed up on the beach.'

Truly amazing - diving this close to the shore

and seeing these weird, weird creatures.

That's a pretty incredible dive.

About 130 miles from Dover is the city of Portsmouth,

the place with centuries of maritime history,

a fair proportion of which is connected directly or indirectly with the Royal Navy, down there.

Her Majesty's Naval Base Portsmouth currently harbours two-thirds of the Navy's surface fleet.

But the city's proud naval tradition goes back nearly 1,000 years,

with many decisive military campaigns being launched from here.

'The question is, why here?'

Why was Portsmouth chosen above other ports on the south coast to be home of the Royal Navy?

Archaeologist Mark Horton is in the historic dockyard to find the answer.

The harbour at Portsmouth has a lot to recommend it, but in many ways

its trump card has nothing to do with its physical geography

and everything to do with politics.

For much of our history, England was at war with her continental neighbours.

First the French, then the Spanish, and then the Dutch.

In those battles, it was considered important to have a harbour as close as possible to the enemy.

For the Spanish wars, that meant Plymouth.

For fighting the Dutch, Chatham in Kent was best.

But it was the French wars that were begun by Henry VIII that really made this place important.

Henry created the Royal Navy in 1525 and decreed that Portsmouth should be its home.

Through fighting the French 7 times in 290 years,

Portsmouth grew from 1,000 people in 1545 to over 30,000 in 1800.

Now the docks were home to 684 ships and were the largest industrial complex in the world.

'But things for Portsmouth were about to change again.'

Just listen to that wind to the rigging.

The Victory, where Nelson defeated the French 200 years ago at the Battle of Trafalgar.

But ironically, it was that victory against the French that changed the role of Portsmouth for ever.

From the base where we fought the French, to the place

where we patrolled the world and fulfilled our imperial ambitions.

For the next 200 years, Portsmouth's growth was driven more

by technological invasion than military need.

'The move from sail to steam in the 19th century saw the biggest expansion.'

It's the sea just the other side of those somewhat rusty gates.

This is the number six dry dock, one of around 20 here.

Portsmouth was not just the centre of the naval operations,

but also an important dockyard, where ships could be built and comfortably repaired.

As the ships got larger and larger, so the dry docks themselves had

to get bigger and bigger to keep pace with technological change.

In the 21st century, warfare continues to change.

'So what is the future for our oldest naval base?'

For the surface navy, the escorts and the aircraft carriers,

this is where it's all at, yes.

And does it still work as a harbour?

Is it suitable for the modern navy?

Oh, very suitable. There's a large investment programme

going on to make sure it continues to be suitable, continues to evolve to meet modern requirements.

Portsmouth is here because of medieval monarchs, Henry VIII and the French.

I think the reason he chose it was because France was the enemy.

Today that is not the case.

Do you think, in 500 years' time, there will be a base here at Portsmouth?

As long as we've got a navy, it will still be here.