While diving, someone boards the Mariner's boat and steals the fruit from his tiny lime tree. He lives by recycling his own urine as drinking water and scavenges for artifacts on the ocean floor using a diving bell with a timed pulley system. One such survivor, known only as The Mariner ( Kevin Costner), travels the globe on his trimaran. The survivors of the ancient deluge have had to adapt to the new world. At an unspecified point in the future, a narrator explains, the polar ice caps have melted covering the Earth in an endless ocean.The synopsis below may give away important plot points. But the Mariner, Helen and Enola are pursued by Deacon and the Smokers, when The Mariner learns the tattoo on Enola's back is in reality a map that will lead them to Dryland. When the Atoll is attacked by The Smokers led by their evil leader Deacon, a woman named Helen and her adopted daughter Enola bribe The Mariner to take them to Dryland, believing The Mariner has been there.
Arriving at an Atoll, a mysterious drifter without a name called The Mariner is sentenced to death when the community discovers he is a mutant. In "Waterworld" drifters sail across the waters of the world on their man-made ships, trading for supplies and salvaging what is left of civilization, communities of survivors live in towns called "Atolls", and a force of evil pirates "The Smokers" travel across Waterworld in search of a mythical island called "Dryland". In the future, the Earth is engulfed with water when the polar ice caps melted, leaving the lands and civilization beneath the sea.