Super Friends (1980)

The Scaraghosta Sea (2x17)

:

When a submarine is sucked into a giant whirlpool, Aquaman takes Batman and Robin to an underwater ship's graveyard. There they discover that the crew of the submarine is being held hostage by a groups of pirates who are intending to use the submarine to get back to the surface. The SuperFriends must rescue the hostages and stop the pirates.