Anthony Perkins and Charles Bronson got along very well during filming. Perkins said Bronson "was a doll" to work with.
Althoough this is a French film, all three lead actors are actually American. The rest of the cast is European. In addition, the film was shot in English.
One of the few films (other than Diamonds are Forever) to show the Seaspeed, a propeller-driven raft boat that could carry many passengers, and quickly.