Discoveries Underwater

Treasure Is Trouble Narrated by Tim Pigott-Smith In 1622 a Spanish galleon, the Nuestra Senora de Atocha, sank in a hurricane off the coast of Florida. She was carrying a cargo worth an estimated 400 million dollars. The wreck was found 350 years later by a treasure hunter and former chicken farmer, Mel Fisher , whose dedicated quest to find the Atocha is now legendary. For years the main treasure eluded him but in 1985 he at last discovered the so-called 'motherlode'. The adventure stories of the search for the Atocha and of the salvage of a British East Indiaman sunk on the Goodwin Sands are told in tonight's film. But should historic shipwrecks provide an excavation free-for-all for private profit or should they be preserved by the state for posterity?

Captain Nemo's world, 20,000 leagues under the sea, is usually thought to be a fantasy of the imagination of Jules Verne. Modern divers have proved that the riches of that world are real and accessible. But that dream of exploring the underwater world has a reality nearly 500 years old. Divers in the past were capable of incredible feats of courage and daring. Roman galleys of the Emperor Caligula were discovered, bronze cannons weighing over four tons were successfully raised, cases of silver bars were recovered from remote islands in the Atlantic - even a basic aqualung was invented 100 years ago. For this film these events have been reconstructed by modern divers using these ancient machines to demonstrate the bravery and skill of early divers whose quest was for that new world.

From the lochs of Scotland, and the lakes of Switzerland to the flooded cave systems of Florida, the search for prehistoric man is under way on a global scale. There are over 350 man-made islands, or crannogs, in Scotland alone. Teams of divers are now working their way into the heart of these Bronze Age dwellings. In Switzerland, diving under the ice, archaeologists are revealing the foundations of prehistoric villages: sophisticated communities, where people specialised in pottery and bronze. In a 250-foot-deep sink hole in Florida, a diver discovered human remains. When the skull was brought to the surface, the brain was still intact. It was radiocarbon dated at 11,000 years old. Underwater archaeology is helping to rewrite history books and changing views of prehistoric man.

The warship is the most potent symbol of power at sea and the spearhead of technology afloat. In any century their loss in battle or by storm or disaster has always been a great tragedy and the basis of great myths and legends. Today these legends have been made reality by the skills of marine archaeologists who have brought legendary ships like the Wasa and the Mary Rose back to light. Even more spectacular survivals remain underwater, still lying where they sank, now to be revealed by a new generation of archaeologists. Space-age technology, the same which found the tragic remains of the shuttle Challenger is used to chart the reality of America's most famous civil war battleship, the USS Monitor, a ship which revolutionised the navies of the world.

The bulk of the world's trade has always been carried by sea, by sailing ships linking different peoples and cultures and bearing not cargoes of riches but the commodities of everyday life. The story of these ships is full of excitement, tragedy and inspiration. The Amsterdam, entombed in the mud off Hastings since 1749, still loaded with an entire cargo. In the harbour entrance of St Peter Port a unique Romano-Celtic vessel of the time of Julius Caesar - recently snatched to safety from the paths of the Channel ferries. And, in Bermuda, the Sea Venture, whose loss in 1609 was immortalised by Shakespeare in The Tempest. In bringing their stories back to life, marine archaeology is, in Sir Mortimer Wheeler 's phrase, 'not digging up things but digging up people'.

The classical world of Greece and Rome is rife with stories of destruction and of great cities like Atlantis being lost and swallowed up by the sea. But one of the greatest sunken cities lies not in the Mediterranean, but across the Atlantic, in the New World. Port Royal, Jamaica, was the centre for buccaneers who raided Spanish galleons laden with treasure. Under the leadership of the famous pirate Captain Morgan, Port Royal came to be known as the Sodom and Gomorrah of the New World, the wickedest city on earth. But in June 1692, an earthquake devastated the town. Over 3,000 people were killed or drowned, as the city slipped beneath the sea. Today, a team of divers led by Dr Donny Hamilton from Texas A and M University is uncovering the town.

More new discoveries have been made underwater in the last 25 years than ever before. Unique aeroplanes, submarines and great ships - like the Titanic. What should be done with them? Salvage them for scrap or save them as historic monuments? In Scapa Flow, every year, the Royal Navy conducts a service of remembrance over one of Britain's biggest war graves - HMS Royal Oak. At Pearl Harbor, Hawaii, is a similar emotive war grave - the battleship USS Arizona. The island of Guam in the middle of the Pacific was the scene of some of the fiercest fighting in the Second World War. There, a Japanese cargo ship, sunk in 1944, lies alongside a German auxiliary cruiser, sunk in 1917. A unique memorial to two world wars.

Tim Pigott-Smith In the early 1960s a young archaeologist Dr George Bass donned a wetsuit and aqualung, learned to dive and began excavating an ancient shipwreck lying on the seabed off the coast of Turkey. Since then his pioneering techniques in the Mediterranean have led to the discovery of early ships laden with amphorae; cargoes of copper, silver, bronze and gold; and, even more precious to the archaeologists, evidence of the ships themselves. Influenced by Bass, British archaeologist Mensun Bound is attempting to excavate an Athenian wreck of the fifth century BC. It lies among the acidic sulphur bubbles and hot lava of an underwater volcano off Sicily. But Bass, meanwhile, must decide whether to take one last dive on the most spectacular wreck of all. It sank 3,500 years ago in the Bronze Age. Could it be the oldest shipwreck in the world?