During the sex scene at the end of the film, when Captain O'Day and Annie are "marooned" in the middle of the Caribbean, the island and beach are visible in the background of several shots, as are rocks and logs floating in the water.
At the very end of the film the surviving couple is waving to a passing steamship from their rowboat (who supposedly "made it to the shipping lanes" even though you can see the waves lapping up on the beach at far camera right). Just as the scene cuts to a long-distance shot of the rescuing ship, you can see the head of a crew person who has been holding the rowboat steady pop up from behind the far side of their boat.
During the scene where Captain O'Day and Annie are having sex on the giant log, a cameraman can be spotted on the left of the screen.
During the scene where Captain O'Day and Annie are having sex on the giant log, a cable hits the camera lens.