Air date: 2021-04-26

Runtime: 44 min

Research teams win special permission to investigate two wrecks from World War I lost in the Orkney islands, the warships HMS Hampshire and HMS Vanguard.

Air date: 2021-05-03

Runtime: 44 min

Newly discovered vessels from the Spanish Armada and the Dardanelles campaign in Turkey during the First World War, shedding new light on these famous failed invasions.

Air date: 2021-05-10

Runtime: 44 min

The tragedy of the Empress of Ireland, Canada's 'Titanic'; and El Faro, which was caught up in a tropical storm in 2015. Both wrecks show how quickly danger can rise up at sea.

Air date: 2021-05-17

Runtime: 44 min

The discovery of three German U-boat wrecks, including the world's first ever stealth sub, reveal dramatic stories of 20th-century conflicts at sea.

Air date: 2021-05-24

Runtime: 44 min

Investigations off the coast of Scotland reveal one of the greatest acts of defiance in wartime history, dating all the way back to World War I