The war at sea is one of the most famous and, nevertheless, most closed topics of the Second World War. The Soviet fleet, both military and civilian, was not ready for such large-scale operations in the conditions of an “unlimited” war on communications. The not-so-rich state could not allocate enough funds to re-create what was once the second or third fleet in the world. The effectiveness of the actions of the Soviet fleet was quite low, which did not prevent, however, many glorious pages from being written in the history of the Patriotic War. On June 22, 1941, in the territorial waters of Sweden, off the island of Gotland, the first Soviet steamship Gaisma, belonging to the Lithuanian State Shipping Company, was torpedoed and sunk. German torpedo boats were based in “neutral” Sweden. So, at 06.10 am Central European time, Soviet sailors entered the Great Patriotic War.