The first film directed by screenwriter John Patrick Shanley, it was also the first of three films pairing Hanks and Ryan. Despite positive reviews from noted critics like Roger Ebert, Joe Versus the Volcano was considered a box office flop, and one of Hanks' minor films. Since then, it has attracted a cult following.
The next day, Joe is visited by wealthy industrialist Samuel Graynamore (Lloyd Bridges), who has a proposition for him. The tiny Pacific island called Waponi Woo is rich in deposits of a mineral called "bubaru that Graynamore needs to manufacture superconductors. The inhabitants of the island, known as the Waponis, will let him mine the mineral, provided he can solve a problem for them. They believe that the volcano on their island must be appeased by a voluntary human sacrifice once every century, but none of the Waponis is willing to volunteer this time around. If Graynamore can provide a willing victim, he can have the mineral. Graynamore offers Joe the opportunity to "live like a king, die like a man." He further offers Joe credit cards to pay for whatever he wants, as long as he jumps into the volcano at the end. With nothing to lose, Joe agrees.
Joe spends a day and a night on the town in New York, where he solicits advice on style and life from wise chauffeur Marshall (Ossie Davis). Joe purchases an Armani tuxedo; for his valued assistance, Marshall also gets a tuxedo. Joe also buys four top-of-the-line, handcrafted, waterproof steamer trunks from a fanatically dedicated luggage salesman (Barry McGovern).
Joe then flies to Los Angeles, where he is met by one of Graynamore's daughters, Angelica (also played by Ryan), a shallow socialite who cautions him not to tell her anything, as she cannot keep a secret ("Daddy says I'm a flibbertigibbet!"). The next morning, Angelica takes Joe to a yacht owned by her father. Among the crew is her half-sister, Patricia (Ryan again). She had reluctantly agreed to take Joe to Waponi Woo after Graynamore promised to give her the yacht in return.
After an awkward beginning, Joe and Patricia begin to bond. Then they run into a typhoon. Patricia is knocked unconscious and flung overboard, but Joe rescues her. Lightning strikes the yacht, sinking it. Fortunately, Joe is able to construct a raft by lashing together his steamer trunks. Patricia does not regain consciousness for several days. Joe rations the small supply of water for her, while he gradually becomes delirious from thirst. Joe experiences a revelation during his delirium and thanks God for his life. When Patricia finally awakens, she is deeply touched that Joe gave her all the water. They then find that they have fortuitously drifted to their destination, Waponi Woo.
The Waponis treat them to a grand feast. Their chief (Abe Vigoda) asks one last time if anyone else will volunteer, but there are no takers and Joe heads for the volcano. Patricia tries to stop him, declaring her love for him. He admits he loves her as well, "but the timing stinks." Patricia gets the chief to marry them, which he hastily does.
Afterwards, Patricia refuses to be separated from Joe. When he is unable to dissuade her, they jump in together, but the volcano chooses that moment to erupt and they are blown out into the ocean. The island sinks, but Joe and Patricia are rescued by their trusty steamer trunks again. At first ecstatic about their miraculous salvation, Joe puts a damper on things by telling Patricia about his fatal brain cloud. She recognizes the name of Joe's doctor as that of her father's crony and realizes that Joe has been lied to. He isn't dying and they can live happily ever after if they survive being adrift at sea on raft made of steamer trunks.
According to people close to Shanley at the time, the story is based on a near-death experience Shanley had and is his attempt to describe and explain the altered outlook on life he adopted as a result.
Shanley wrote two songs for the movie, "Marooned Without You" and "The Cowboy Song", the former used thematically throughout and the latter performed by Tom Hanks on the ukulele.