The song performed by Su and Lou (You're Leaving Me) wad originally performed in Spanish by a singer named Jeanette in the early 70's. The song is originally called Porque Te Vas (Because You're Leaving).
The skipper's ship the Bella Donna is a reference to director and screenwriter Peter Keglevic's 1983 film Belle Donna.
For some reason, the film became regarded as a public domain title in the U.S. years after its release. Floods of VHS and DVD releases have been floating around the market, usually of poor quality.