The hot tub was not built properly or chlorinated. Michelle Pfeiffer, her double, and Mel Gibson got skin rashes and splinters from the wood. Production shut down for a few days while Pfeiffer recovered from her rash.
Michelle Pfeiffer reportedly did not get along with writer/director Robert Towne. He called her "the most difficult actress I have ever worked with." This was most likely due to Towne's reputed perfectionism and the fact that Pfeiffer was going through a divorce.
Before shooting began according to producer Thom Mount, Warner Bros. pulled out of the film because of issues with the screenplay citing that the good guy was an ex-drug dealer and the cops and feds are the bad guys.
Warner Bros. agreed to finance and produce this film after Robert Towne agreed to a settlement of 2.5 million dollars after they had pulled out of the post-production of his directorial debut film, Personal Best (1982). The deal was contingent that the studio would let Towne not only write the film, but also direct it, according to producer Thom Mount.
When Robert Towne was re-working the screenplay for Frantic (1988), he had nearly finished his screenplay for this film. Harrison Ford, the star of "Frantic", immediately became interested and agreed to star, but eventually dropped out in pre-production because of personal conflicts with the role. Towne and Thom Mount then flew to Australia to meet with Mel Gibson and he agreed to star.
The red boat used in the movie is either a 1987 or 1988 Chris-Craft Fittipaldi Equipe 312 Stinger, Limited Edition. The Fittipaldi Equipe was named for Emerson Fittipalidi, the famous Formula 1 and Indy Car driver. The Fittipaldi Equipe version featured an all red paint job, white interior, anodized-blacked out hardware, special plaques, and high-performance Kiekhaefer controls and K-planes. In 2013, someone claiming to own the boat used in the movie listed it for sale.
At the time, Robert Towne was going through legal issues with The Two Jakes (1990), the planned sequel to Chinatown (1974), and it ended up severing his friendship with Jack Nicholson (they have apparently since reconciled). Greg and Carlos each have a speech about friendship that reflects Towne's feelings of betrayal.
According to producer Thom Mount, Alec Baldwin was the original choice to play Nick Frescia and had actually come back twice to audition for the role, but Robert Towne and Mount decided to go in another direction.
When the film went into production, the coach of the Los Angeles Lakers at the time, Pat Riley, was offered the role of Nick. When he turned it down, it went to Kurt Russell. Russell's look for the role was influenced by Riley. Russell was quoted as saying that "Riley's look was right for this film because he was arrogantly confident but not offensive." Russell also used the look and hairstyle of Riley again for fast and furious 7 (2015) and now in fast 8 (2017).
Robert Towne wanted Dale McKussic to go up in smoke at the end of the film, but one of the conditions Warner Bros. set was that he must live. "Gibson's character was supposed to be a moth in the flame," said Towne. "The real high for him was never doing the drugs, but the danger of dealing the drugs."