London, Feb 3: Adolf Hitler's U-boats dominated the seas during World War II, earning notoriety by sinking hundreds of Allied ships.

Now, 60 years on, the Nazi dictator's 'lost fleet' -- the resting place of three German submarines -- has been found in the Black Sea off the coast of Turkey.

The hulls of the submarines--U19, U20 and U23--have been discovered by a team of researchers who established the boats' positions through research in German archives and by sonar studies of seabed, The Sunday Telegraph reported.

"It's one of the least well known stories of the war but one of the most interesting. It is a quite incredible story. To get to the Black Sea these boats had to be taken across the land, and once they got there they had no way out," said Turkish marine engineer Seluk Kolay, who led the team.

The submarines were carried 2,000 miles overland from Germany to attack Russian ships during the Second World War, but scuttled as the war neared its end.

In fact, the vessels formed part of the 30th Flotilla of six U-boats, taken by road and river across Nazi-occupied Europe, from Germany's Baltic port at Kiel to Constantia, the Romanian Black Sea port.

In two years, the fleet sank dozens of ships and lost three of their number to enemy action. But in August 1944, Romania switched sides and declared war on Germany, leaving the three remaining submarines stranded.

With no base and unable to sail home -- the Bosporus and Dardanelles were closed to them due to Turkish neutrality -- their captains were ordered to abandon the U-boats before rowing ashore and trying to make their way back to Germany. However, all the German crews were caught by the Turks.

"This is a significant find because these U-boats were all scuttled, so they should be intact, like a sealed tube. They are unique survivors of the war," Nautical Archaeology Society's Secretary Mike Williams was quoted as saying.