It is rumored that director Kevin Reynolds and Kevin Costner had a huge squabble over the film, resulting in Reynolds walking off the project and left Costner to finish it. Reynolds was quoted as saying that "Kevin should only star in movies he directs. That way he can work with his favorite actor and favorite director".
Kevin Costner was put up, at a cost of $4,500 a night, in an oceanfront villa with a butler, chef, and his own private swimming pool. In contrast, crew members were forced to live in uninsulated condominiums that were subject to temperature swings of up to 50 degrees. This inequity of accommodations contributed to on-set hostility and low morale.
The picture on the wall that Deacon refers as "Old Saint Joe" is actually Joseph Hazelwood, infamous captain who crashed the Exxon Valdez oil tanker into the Alaskan landscape, negligently discharging millions of gallons of crude oil. The base of the Smokers is the Exxon Valdez, as evident when it sinks. The stern rises and the word "Valdez" is visible. The real Exxon Valdez was repaired and renamed the Sea River Mediterranean. It is used to haul oil across the Atlantic.
The map tattoo on Enola's back is in Chinese traditional characters (or Japanese Kanji). The characters in the middle surrounding the arrow are actual coordinates for longitude and latitude. While one number is not quite readable, the others give almost exact coordinates for Mount Everest, which is Latitude 27° 59' N Longitude 86° 56' E. The movie coordinates give: Latitude 27 or 28° 58' N Longitude 86° 56' E.
For the Japanese premiere, Kevin Costner had his private plane flown to Tokyo. However, he failed to get permission to store his plane at the airport for the duration of his trip. He asked the Navy if he could use their airport at Atsugi. They agreed, contingent on Costner showing the movie there, and making a personal appearance.
Jeanne Tripplehorn refused to strip for this film, even though she had done nude scenes before (and would do them after this film). However, she insisted on choosing her body double, as she wanted the naked backside shown to resemble her own. She had the three finalists come into her trailer and drop their robes. She described it as such an odd experience that none of them could stop laughing. In between takes of the nude scene, Tripplehorn remained off-camera to offer a robe or towel to the double.
The 1,000 ton floating set did not have any restrooms, nor were there any on any of the 30 boats used by the cast and crew. The result was that filming had to halt so those in need could be ferried to a barge anchored near the shore which had several portable toilets on it.
Widely considered to be one of the biggest box-office bombs of all time. Although it grossed $255 million from a $175 million production budget, this does not factor in marketing and distribution costs, or the percentage of the gross that theaters keep (which is up to 45% of a film's box office takings). The film came to be nicknamed "Kevin's Gate" after Heaven's Gate (1980) and "Fishtar", after Ishtar (1987), two previous mega bombs.
The studio didn't spend any money researching weather patterns off Hawaii's Kona coast, where the film was shot. If they had, they would have learned that the area was subject to 45 mph winds, which constantly blew the set out of position and ruined shots.
The original screenplay by Peter Rader was pitched as an children's adventure film. In Rader's screenplay the Mariner was a human and the chief defender of the Atoll, whose embarrassing secret was that he enjoyed painting pictures of seahorses; Helen had two of her own children along with the adopted Enola, and the Deacon was a campy, silly villain who dressed up like King Trident, sat atop a throne on the Exxon Valdez, and punished his subordinates by slapping them around the face with a wet fish. Subsequent rewrites by David Twohy and Joss Whedon turned the original script into a much more serious action-adventure film.
A French science fiction graphic novel called Aquablue, created in 1988 by writer Thierry Cailleteau, explores very similar themes as this movie, although it's set in the future where mankind can traverse space, and it takes place not on Earth, but on a hostile water planet called Aquablue where a survivor from a crashed space cruiser and his robot must survive.
Stunt coordinator Norman Howell got hit with compression sickness during filming of an underwater scene and was rushed to a hospital in Honolulu via helicopter. He recovered fairly quickly from the potentially life-threatening sickness and returned to the set a couple days later.
The four-machine gun chassis in the atoll assault scene is called a Maxon Mount. It is comprised of four .50 caliber Browning machine guns and was used as an anti-aircraft battery during World War II. It also came in a two gun mount which was used upto & in the Vietnam War as a Point Defense Weapon.