Their navy was underwhelming during WW2, and between personnel purges, ship and technology obsolescence, lack of budget (11% of defense spending in '41, down to 6% in 1945), and tactical priorities, left the Soviet Navy with only few engagements worth noting.

In the arctic, the Soviet navy was active during the entire war protecting shipping convoys and ports, with a focus on anti-submarine, minelaying/sweeping, and anti-air warfare, with the US and Britain bearing the majority of escort duties. The primary ports were Arkhangelsk and Murmansk, and a lot of their efforts were directed at supporting their fight against Finland, or dealing with german submarines.

The Baltic and Black sea fleets were essentially stuck in ports like Leningrad due to heavy mining and blockading by German forces, however submarines were able to get out and harass a bit. Most surface ships were knocked out by aircraft or subs, or were old dreadnoughts and outdated lend-lease destroyers - many turned into stationary batteries or aa platforms protecting ports.

The pacific fleet remained token and didn't see real action, as the USSR did not declare war on japan until 1945 (after the US already decimated the japanese fleets).

Shore-based planes and flying boats, torpedo motor launches, and other craft played roles. Naval officers and sailors typically found themselves reassigned to the army, infantry and port facilities. There were a few successful submarine attacks, such as the sinking of the Wilhelm Gustloff, and some effective naval land bombardments during sieges and offensives, and several large evacuation missions.

After the war they took possession of a handful of german and Italian ships - greatly bolstering and modernizing their navy overnight.