Sam helps Joe grease up for the big swimming race. In the first shot (close-up), he is greasing Joe's right thigh, and Joe's leg below the knee is clean. The next close-up shows Sam working his way down Joe's calf. In a subsequent long shot, Joe's right calf is greased up to the knee, but his thigh is clean.
During the swim in the middle of the Gulf of Catalina, Joe can often be seen at the water's surface when shown from above, yet his feet are seen close to touching bottom (such as when he believes a shark is nibbling at his toes) when shown from below, making the water only a few feet deep if the case.