Diver Finds Lost WWII Submarine

A Greek diver and researcher has found the HMS Triumph, a special ops British submarine that disappeared in 1942. The wreckage was found in the Aegean Sea, off the coast of Cape Sounion at a depth of 203 meters.

Kostas Thoctarides first learned of the British submarine in 1998 and has been searching for it ever since. He called finding the lost vessel “the hardest mission I’ve ever undertaken in my life.” After scouring British, German, Italian, and Greek archives for details about the submarine and its downfall, he began searching for it. This is the fifth submarine he and his team have found in Greek waters.

Kostas Thoctarides and his daughter, Agapi-Oceanis. Photo: Kostas Thoctarides


The vessel is heavily linked to helping end the German occupation in Greece during the Second World War. “The history of the submarine Triumph is multidimensional and unique in maritime history, and is inseparable to national resistance and the secret services that acted in the dark days of occupation,” Thoctarides said in a Facebook post.

With the help of his daughter, who is the first certified female ROV pilot in Greece, Thoctarides found the submarine with an Echo Sounder. They then used ROV’s to explore the site due to difficult conditions. The strong underwater current and depth meant it was almost impossible for divers to reach the site themselves. Footage shows that the submarine’s periscopes and hatches were down when it sank, suggesting that the HMS Triumph was carrying out a deep dive when she met her watery end.

Photo: Kostas Thoctarides/Facebook


The front section of the submarine showed severe damage. The search team believe that an explosion likely sank the vessel. They are unable to tell if the explosion was internal or external. They are now working with experts to try and decipher exactly what happened.

Photo: Kostas Thoctarides/Facebook


Thoctarides was careful to treat the site with care and respect as it is the war grave of 64 people. When it sank on January 9, 1942, there were seven officers, two commandos, and 55 crew members on board. Triumph launched in 1938 and completed 20 successful missions during the Second World War.

HMS Triumph. Photo: Royal Navy Submarine Museum


The submarine brought down a number of enemy ships and submarines during her missions but was best known for its involvement in covert operations. Notable missions include recusing trapped soldiers from Egypt and involvement in Special Operations Executive projects. The SOE was a secret British WWII operation tasked with “setting Europe ablaze” by Winston Churchill. Agents would work with local resistance fighters to sabotage and subvert the enemy. HMS Triumph was part of one of the first SOE missions.

Photo: Kostas Thoctarides/Facebook


Records show that Triumph’s last mission saw her secretly land a British intelligence team in Despotikos Bay, near Antiparos on December 30, 1941. She was then scheduled to help 30 fleeing Britons from the island of Antiparos on January 9, 1942. The submarine never appeared and all 30 escapees were arrested. Two weeks later, the submarine and all 64 crew members were listed as missing in action.

Rebecca McPhee

Rebecca McPhee is a freelance writer for ExplorersWeb.

Rebecca has been writing about open water sports, adventure travel, and marine science for three years. Prior to that, Rebecca worked as an Editorial Assistant at Taylor and Francis, and a Wildlife Officer for ORCA.

Based in the UK Rebecca is a science teacher and volunteers for a number of marine charities. She enjoys open water swimming, hiking, diving, and traveling.