About 2/3rds of the way through the movie, when Frank motors away from the pier in his motor launch, the name of the boat is clearly visible just below the gunwale, right astern - "Cassis" (French for black currants, also the name of a commune (district) in Marseilles). Moments later, as we see Frank out at sea in the boat, the name on the boat is "Manon" (a woman's name).