Problems encountered during filming led to massive budget overrun, and it held the dubious distinction of being the most expensive film ever made at the time. Some critics dubbed it "Fishtar" and "Kevin's Gate" (references to the notorious flops Ishtar and Heaven's Gate). However the movie actually made a little more than $100 million revenue with worldwide sales. With a budget of $175 million, the film grossed $88 million at the U.S. box office, which made it appear to be the all time box office bomb. But it topped its budget once overseas take was taken into account (grossing $176 million in foreign markets ).
Adjusted for inflation and expressed in 2006 dollars (USD), the budget for the movie was $231.6 million, and grossed $116.8 million at the U.S. box office and $232.9 million at the foreign box office.
About five hundred years in the future, the polar ice caps have melted due to unexplained events, though human action is hinted when the Mariner exclaims "We did it". The Earth's surface is almost entirely water. The surviving humans have forgotten the past and believe in a modified creation myth in which God created the world as a ball covered with water, but that there is also dry land somewhere out there.
The survivors can be classified into four groups:
The antihero is a trader known only as the Mariner (Kevin Costner) who comes into an atoll to trade. He is a mutant, a new step in evolution to accommodate the changes in climate, with webbed feet and gills. The atollers, fearful of mutants, try to kill him. At that moment, however, the smokers arrive in a raid on the atoll. They are searching for a girl living there named Enola, who has what appears to be directions to dry land tattooed on her back. Her caretaker is Helen, the atoll's shopkeeper, and they plan to escape with Gregor, the atoll's resident astrologer, for dry land because, like the Mariner, they don't fit in.
But Gregor's escape balloon escapes too early with him on it, leaving Helen and Enola stranded. They escape with the Mariner, who seems ill-pleased with their company.
Chasing them is Deacon, who is the 'captain' of a derelict oil tanker, the Exxon Valdez. He also wants to get to dry land, and has a number of skirmishes with the Mariner in his attempts to get Enola back.
Helen wants to know where the dry land went. The Mariner, who can breathe underwater, puts her in a diving bell, and swims down to a sunken city on the ocean floor to show her. While they are distracted beneath the ocean's surface, Deacon and the smokers board the boat. Enola hides to avoid capture. When Helen and the Mariner resurface, Deacon orders them to tell him where Enola is. When they both refuse to talk, Deacon pretends to shoot them and Enola emerges from hiding and is captured. After he has Enola, Deacon has his machine gunner open fire (the Mariner and Helen dive underwater to escape) and burn the Mariner's boat. Since Helen cannot breathe water, the Mariner offers, "to breathe for the both of [them]" resulting in a prolonged underwater kiss of life.
They are later rescued from the wreckage of the Mariner's trimaran by survivors of the atoll attack, including Gregor in his balloon.
Using a jet-ski, the Mariner chases down the Exxon Valdez and boards it. Deacon is having a great celebration, during which he tosses gifts to the crew of the Valdez, proclaiming they have found the map to dry land. After they have all left, the Mariner walks out onto the deck and threatens to throw a road flare into the oil tanks unless Deacon releases Enola. He refuses, saying that the trader would be crazy to blow up the ship. He throws the road flare in.
The ship explodes, and the Mariner escapes with Enola rescued by Gregor by climbing a rope dropped from his balloon. The Deacon, still alive, grabs the rope and tries to pull Enola. The Deacon loses his grip and falls into the water. Still alive, he pulls out his pistol and shoots at the balloon, hitting one of the lines, causing Elona to fall back into the sea. The Deacon waves to the 2 other surviving Smokers to grab the girl. The Mariner ties a rope around his ankle and bungee jumps down to grab Enola. The Deacon smashes with the other jetskis and blows up. Gregor figures out the map, and steers his balloon toward what does turn out to be dry land. Gregor, Enola, Helen and the others start civilization anew on the island, which a plaque reveals to be the peak of Mount Everest. Enola, saddened to hear the Mariner leaving, asks why he must go. He explains that he doesn't belong on dry land and that the ocean calls out to him. He finds a boat near the beach, and before sailing off, Enola and Helen look out to him drifting away, back to his old life.
There is currently a show at Universal Studios Hollywood and Universal Studios Japan based on the film. It takes place immediately after the movie, where Helen returns to the Atoll with proof of dry land, only to find her followed by the Deacon, who survived the events of the movie. The Mariner arrives immediately after him, however, and defeats the Deacon and takes Helen back to dry land while the Atoll explodes.