Should shipwrecks be left alone ?
By Chris Summers - BBC News
It is 10 years since a deal to protect the world's thousands of shipwrecks, but the UK and several other major maritime powers are yet to ratify it. Should this underwater heritage be protected or is it acceptable to plunder ?
When a ship sinks and lives are lost, it is a tragedy for the families involved.
For the relatives of the dead, the ship becomes an underwater grave but as the years pass the wreck can become a site of archaeological interest.
In recent years technological innovations have allowed commercial archaeologists, decried by some as "treasure hunters", to reach wrecks far below the surface.
The most famous of them all, the Titanic, is more than four miles down and to get there as film director James Cameron has shown, involves using "robot" divers which are prohibitively expensive - around $50,000 (£32,000) a day.
Salvage firms are most interested in ships with cargoes of gold and silver, ceramics or other valuables.
In November 2001, the Unesco Convention on the Protection of Underwater Cultural Heritage was finally adopted.
But 10 years on, it still has not been ratified by the UK, France, Russia, China or the US, and commercial archaeologists continue to locate wrecks, remove their cargoes and sell them off.
"The convention has not been ratified yet because of the issues it throws up about the cost of implementing and policing it," a spokesman for the UK Department for Culture, Media and Sport, says. "Discussions continue within government, but ratification is not currently seen as a priority."
In September Britain's Department of Transport announced it had signed a deal with Odyssey Marine Exploration for the salvage of 200 tonnes of silver, worth up to £150m, from the SS Gairsoppa, which was sunk by a German U-Boat in 1941.
The British government will get 20% of whatever Odyssey recovers but Unesco says the deal broke the spirit of the convention.