Enemy submarines using torpedoes that would win this naval battle and send you to feed the fish. Three hits is enough, what they might have succeeded.
Answer them the same! Rain down them deep mines, bombs, and incinerate them by rays of hatred! Destroy as many submarines as possible and not let them beat you in this sea battle.
Sometimes the waves appears repair kit that will restore the damaged one - in a hurry to pick up until the torpedo hit him.