ORP Kaszub was a small submarine of Soviet M class (postwar series XV) which served in the Polish Navy from 1954 to 1963.

The most notable event in the submarine's history was the grounding near Krynica Morska on November 28, 1957.

The commander of the ship made an unsuccessful attempt to get off the shoal, regardless of the extremely difficult conditions (strong wind, high waves, and low temperature).

During the operation, two crew members lost their lives, and the ship was forced by the sea onto the beach.

The submarine remained there until a rescue operation conducted by several units allowed Kaszub to be pulled into deeper water.