A deepwater dive team search the seabed off the coast of Northern Ireland for the forgotten shipwrecks of WW2's Battle of the Atlantic. Jules Hudson helps identify the wrecks and reveals how the city was critical to Allied victory.

Maritime historian and underwater explorer Ian Lawler leads a team of deepwater divers to the ocean floor off Northern Ireland. He and the team are searching for the forgotten shipwrecks of WW2's longest, most epic naval campaign, the Battle of the Atlantic.

Presenter Jules Hudson joins Ian and two naval experts as they attempt to piece together the stories of the wrecks using the dive team's underwater footage. What they discover reveals the unique role played by the city of Derry-Londonderry in fighting the battle. And while the divers continue their mission at sea, Jules hunts on land for the final clues to the forgotten story of the battle.

To begin, the dive team discover the wreck of an Allied escort vessel sunk in battle 40 miles off Donegal. They also discover the wrecks of the German U-boats that prowled Northern Ireland's coastline looking for targets. Meanwhile, in Derry, presenter Jules Hudson uncovers the remains of a massive US military base. And the residents of the city remember the war years, recounting their memories of life on the front line. Show less