LUSITANIA, the Cunard Line steamer sunk by a German U-boat off the coast of Cork in 1915 drowning all 1,200 on board, is one of the most famous shipwrecks in Irish waters. But a new study has discovered that the seas surrounding Ireland are littered with evidence of thousands of other maritime tragedies, with as many as 15,000 wrecks resting on the seabed.

Following one of the most extensive research programmes ever carried out by underwater archeologists, the number of wrecks discovered has soared from an initial examination six years ago of just 7,000 vessels.

A search of Lloyd’s List, the shipping insurance newspaper, has discovered 12,000 references to Irish wrecks going back centuries. A list of 11,000 has been compiled by the Department of the Environment’s underwater archaeology unit.

Separately, the Irish National Seabed Survey (INSS) has found more vessels on its scans. It has identified the decaying remains of more than 100 shipwrecks around the Donegal coast alone.

Karl Brady an archeologist with the INSS said: “We are coming across more and more wrecks as we go along. At the moment we are planning to sort and co-ordinate all the information on a computer database and that should give us a clearer picture.

“When we get it all on a database we will be able to analyse it better. We estimate we will eventually have up to 15,000 wrecks on the inventory.”

Brady said the wrecks will range from prehistoric times up to 1945 and will include dugouts, Viking longships, sailing vessels, steamers, great liners and wartime sinkings.

There are thousands more wrecks from ancient times that will never make it on to the inventory. “There is a lot of information for the 19th century and there is some for the 18th, but once you get to the 16th century and to medieval times we have very little information,” said Brady.

The research is providing new details about the ships’ cargo, the fate of passengers and crew, and attempts at salvage. “There are extraordinary stories, and survivor accounts provide a more personal and human aspect of the tragedies,” he said.

The shipwreck research project is not only leading to the discovery of previously unknown vessels but is also providing fresh details about a range of known wrecks.

The HMS Looe was a very unusual Williamite warship that was only a year old when it was sunk at Baltimore in Co Cork in 1697. The ship was patrolling off west Cork guarding against a French invasion and pirate raids.

Connie Kelleher, an underwater archeologist, said the Looe was a prototype man-of-war known as a “one and a half-decker”. Only 34 of them were ever built. After it ran aground on rocks the captain was court-martialled but acquitted. About 10 of the Looe’s cannons have been discovered.

La Trinidad Valencera, which sank off Kinnagoe Bay in Co Donegal in 1588, was the fourth largest ship in King Philip II of Spain’s ill-fated invasion armada. A requisitioned merchant Venetian galley weighing 1,100 tons, it was used to carry armaments, particularly large bronze siege guns that would have been used against British towns and cities if the invasion had succeeded.

Discovered by members of the Derry sub-aqua club, many artefacts have been recovered. Cannon and carriage wheels have been exposed on the site.

The underwater archaeology units are investigating several other Spanish armada wrecks. These include La Surveillante, the most important and probably the best preserved wreck of its kind in Irish waters. It was part of the ill-fated French expedition to support the United Irishmen and sank off Bantry Bay in Cork in 1797.

The most significant find of recent years is The Great Lewis which sank off Waterford harbour in 1645. Archeologists are almost certain the wreck, which is intact in the sand and silt, was Oliver Cromwell’s flagship and claim its importance “cannot be overestimated”.

The details on the discoveries will be kept on the unit’s archive and an inventory published in four volumes.

Times Recommends

• Rio Tinto four held as China prepares case
• Diplomats must keep heads down and trousers up
• When in Rome should one make like Berlusconi?