[1] German U-boats began operating in the Black Sea during late 1942, without scoring any hits while the Romanian submarine Delfinul departed for her final patrols.

A separate action was accomplished (alongside other Soviet Navy units) to supply and later evacuate troops from the Siege of Sevastopol.

While carrying away men from the besieged city, Soviet submarine ShCh-214 was torpedoed and sunk in surface action by Italian MAS boats on 19 June.

A second loss occurred on 26 June when Soviet submarine "S-32" was sunk, most likely by German bombers (while Italian midget-submarines CB-3 and CB-4 also take credit of this victory but their attacks did not matched with S-32's last mission).

Soviet submarines have been extimated to have sunk 13 targets in the Black Sea (13,000 GRT) but only 6 of them directly supporting Axis operations on the Crimea.