Submarine (The Sea Devils)

During the Sea Devil's attacks on shipping, Captain John Hart arranged for a submarine to be dispatched to investigate the disappearances. Commanded by Commander Ridgeway, the submarine was attacked by the Sea Devils and was overpowered and was driven down to the sea bed. The Sea Devils boarded the submarine and prevented any attempt to escape to the surface. They killed a few members of the crew.

The Sea Devils commandeered the submarine and used it to travel to the part of the island where the Master was incarcerated and took him back to their base. The Third Doctor was able to escape with the submarine after using a torpedo to blast their way past a forcefield the Sea Devils had activated to trap the ship inside.

The submarine was later part of a taskforce organised by Walker to attack and destroy the Sea Devils after their invasion of HMS Seaspite, but the Sea Devils were destroyed by the Third Doctor before the attack took place. (TV: The Sea Devils)