This was produced by Gregory Peck, and he was very active during its promotion.
David Cassidy was touted as a possible male lead but the deal fell through, either because Cassidy's asking price was too high or there was conflict with his Screen Gems television contract.
Since the movie was made in the mid-1970s it does not keep to the time setting of 1965-1970 in that the boat used for the Dove was a 1973 Ranger 23 sloop, designed by Gary Mull. It was a very popular inexpensive boat for its day, having a relatively shallow hull with a fin keel (not like the full-bodied traditional design of the boat it portrays). The production crew acquired no less than five (some sources say nine) of the same model boat and staged them at filming locations around the world. It is not known if they were returned to the United States or if they were simply sold where they were used for filming.