Expedition leader Konstantin Bogdanov told RIA Novosti that the sub, which perished in 1942 while moving from Kronstadt to the area around Lavensari Island, was found resting at a depth of 50 meters, not far from Seskar Island, covered in netting.
The vessel had been traveling along the surface before being hitting a mine which tore off the front of its hull.
'Reverence to the Ships of the Great Victory' expeditions have been held annually since 2005. In this time, over ten wrecks have been discovered.
Built in Leningrad in the late 1930s, the Sh-405 entered into service with the Baltic Fleet in June 1941, just days before Nazi Germany and its allies declared war on the Soviet Union. The vessel sunk on June 13, 1942; all 39 officers and crew perished. 88 Shchuka subs were built, with 35 of them lost during the war. The vessels were each armed with ten torpedoes and 2x45 mm semi-automatic guns, and had a total range of 11,000 km. Soviet subs operating in the Baltic Sea were tasked mainly with disrupting German supply lines and sinking Kriegsmarine transport ships.