The SS Claridonnote is an old ship that is scheduled to be scrapped after just a few more voyages. Cliff (Stack) and Laurie Henderson (Malone), alongside their daughter, Jill (Tammy Marihugh), are relocating to Tokyo and decide to sail there on board the ship. A fire in the boiler room is extinguished, but not before a boiler fuel supply valve is fused open. Before the Chief Engineer can manually open a steam relief valve, a huge explosion rips through the boiler room and the many decks situated above it, killing him and some of the passengers and trapping Laurie under a steel beam in their state room, in addition to opening a huge hole in the side of the ship. From then on, it's up to her husband and a crewman to cut her free before the ship goes under.
This film features examples of:
- Anyone Can Die: Unlike modern disaster epics, this is mostly averted; the only really unexpected death in the entire movie is the Captain, crushed by a falling funnel.
- Driven to Suicide: Laurie attempts to cut her wrists when she thinks there is no hope of rescue before she drowns. She's unable to go through with it.
- Fight to Survive: The SS Claridon suffers a boiler explosion that damages the ship so much that it begins to sink. One passenger is trapped in her cabin by a falling beam and her husband and a crewman must cut her free before the ship goes under.
- Ignored Expert: Another aversion from later disaster movies. The captain is guilty of over-caution at times, but he does order the evacuation in time to save the passengers and (most) of the crew.
- The Last Title: The Last Voyage.
- Loads and Loads of Characters: Played straight with the crew, but the civilian characters number only three (allowing them to have an entire subplot to themselves).
- No Antagonist: Nobody is behaving villainously; the ship they are on is simply old and thus at much higher risk for critical failures.
- Outrun the Fireball: Averted, as the film goes for suspense far more than for action sequences.
- Primal Fear: Laurie, as the water begins to rise around her, faces drowning slowly and alone.
- Reasonable Authority Figure: The Captain, quite unlike many other shipboard examples of this trope. He is slow to react to the unfolding disaster, but he listens to his crew and when it becomes obvious the ship is doomed, orders everyone to evacuate. Nearly all of them make it off the boat safely. But not him.
- Sinking Ship Scenario: The film centers on the sinking of an aged ocean liner in the Pacific Ocean following an explosion in the boiler room.
- Too Dumb to Live: The Chief Engineer decides, with steam pouring out a dozen different cracks in the stricken boiler, to start whacking the stuck safety value atop it to try and open it. He blows himself to Ludicrous Gibs instead.
- Trash the Set: The reason the movie has such realistic effects of the cruise ship sinking is simple: the producers really did sink a ship, the The SS Île de France
- Ur-Example: One of them. Though preceded by A Night to Remember as the first major disaster epic, it took a very different course then a lot of what was to follow.
- What Happened to the Mouse?: The last scene of the plucky Second Engineer Walsh - a fairly important character in the story - is jumping overboard and swimming away when the ship enters its final death throes.