Fatty, his wife and mother-in-law are on a ferry to Catalina Island for an outing. So are Mabel and her father. Mabel and Fatty flirt with each other, and Fatty tosses her father overboard, thinking he is another suitor. The boat docks and the two go their separate ways. Mack Swain tries to pick Mabel up, too. All go to rent bathing suits, Fatty locks Mack in a dressing room with mother-in-law. Fatty and Mabel feed a large fish to a seal at the water's edge, and then engage in some graceful and comic diving. Swain, Avery, Durfee and Davenport see them diving and corner them...everyone's relationship to each other is revealed.