According to the documentary included with the DVD, included in the final cut of the film is a scene where Al Pacino's character gets rudely bumped into on 5th Avenue while trying to court Ellen Barkin's character. According to the director this was an unscripted moment caused by a real New Yorker and not an extra. Pacino incorporates the moment into his performance and continues without missing a beat.
When Frank Keller is trying to convince his Lieutenant to let him try the restaurant sting operation without wearing a wire, he says "What is she gonna do, confess? Shoot me? We're in a restaurant!!" Al Pacino famously played Michael Corleone in a scene where he shot a cop in a restaurant, which was also supposed to be improbable.
Ellen Barkin, in a 2011 interview with Chicago's Huffington Post, said that this movie was not her best work, didn't think director Harold Becker liked her but the picture did make her a household name. The article states that Barkin says that "she was forced into doing the sensual grocery store scene where she caresses yellow peppers while wearing little under her raincoat other than a sly thigh to entice co-star Al Pacino. Barkin said she had a big fight with the director over it since she really didn't want to do it...Pacino was 'brilliant' and 'very generous' to work with, but the reason it's hard for her to watch is when she views Sea of Love (1989) what the audience sees as 'attitude' on her part, is really a 'tenseness'. But through her training in method acting at the Actors Studio, she made her tenseness in that scene work for her in front of the camera. It was her first role where she was cast as 'an object of desire'."
The film represented the end and the start of a four year hiatus for actor Al Pacino and director Harold Becker respectively. Pacino had not made a film for four years since 1985's Revolution (1985) whilst director Harold Becker would not direct another feature film for four years until 1993's Malice (1993).
There are two renditions of the 1950s song "Sea of Love" heard in the movie. This included the original 1959 recording performed by Phil Phillips with the Twilights and a then new 1980s end title version performed by Tom Waits.
One of two late 1980s Hollywood thrillers with a title based on a famous song. The other was Ridley Scott's 1987 film Someone to Watch Over Me (1987). Both movies were set in New York City and both pictures prominently feature their famous tunes in each's film.
In addition to the deleted scenes from the DVD and the Lorraine Bracco scenes from the TV premiere, the theatrical trailer features a glimpse at yet another scene not in the final cut. In it a guy recognizes Keller and draws a gun on him to which Keller does the same and says "Don't you move!".
The interiors and sound stage set sequences for this New York set movie were filmed in Toronto instead of the Big Apple. The exteriors were still shot in New York with most of them being filmed in the city's Upper West Side.
This New York set picture that filmed its location exteriors there featured such locales in the Big Apple such as Queens, The Bronx, Broadway in the 70s, the Taft House in East Harlem, Eighth Avenue, O'Neals Balloon near the Lincoln Center, East 57th Street, West End Avenue, West 84th Street, Amsterdam Avenue and the 59th Street Bridge.
Due to interiors being shot in Toronto and exteriors being filmed in New York, much attention to detail needed to be made for continuity to make sure that portions of shots relating to the same sequences actually matched.
A short fourteen minute behind-the-scenes making-of video documentary was made about this movie in 2003. Entitled, The Creation of: 'Sea of Love' (2003), it is available on some of the DVDs for this film.
The meaning and relevance of this movie's "Sea of Love" title refers to the pool of murdered male victims that have resulted from a series of one night stands derived from lonely hearts advertisements in a New York singles magazine.
The Lonely Hearts advertisement in the singles magazine that the NYPD took out was a poem by Frank Keller (Al Pacino)'s mother written in 1934 while she was in high school. The ad read: "Lady - I live alone within myself like a hut within the woods. I keep my heart high upon a shelf barren of other goods. I need another's touch and smile to fill my hut with songs. I remain; a single, white, male, 42. NYW POB 233".
The movie's title is derived from the classic 1950s song of the same "Sea of Love" name. According to Wikipedia, the 1959 tune was the subject of this movie and was "written by John Phillip Baptiste (aka Phil Phillips) and George Khoury. Phillips' 1959 recording of the song peaked at #1 on the U.S. Billboard R&B chart and #2 on the Billboard Hot 100".