After "The Poseidon Adventure", in which the ship got flipped over by a tidal wave, the ship drifts bottom-up in the sea. While the passengers are still on board waiting to be rescued, two rivaling salvage parties enter the ship on search for money, gold and a small amount of plutonium.

"Before her fate is sealed by the deep, the superliner Poseidon will reveal one last secret."

Credits

Irwin AllenDirector

Michael CaineCaptain Mike Turner

Sally FieldCeleste Whitman

Telly SavalasCaptain Stefan Svevo

Peter BoyleFrank Mazzetti