Cross Current (1971)
A speed-boat racer suffers amnesia after an boating accident and goes to his isolated villa to recuperate. His relationship with his wife is troubled, so he starts an affair (sort of) with the another woman, which results in one of the three of them being shot. But there are several more twists--and more murders--to come. amnesia, murder, memory loss, whodunit, extramarital affair, speedboat
ETC.
