Tom is underwater and looking at seahorse passing by. He notice Jerry as a mermouse swimming with them. He tries to catch Jerry but Jerry swims away. Jerry grabs the hook and hands it over to Tom. Tom is pulled out of the sea by the hook. Jerry tries to run away and Tom comes swimming back. Jerry hides in a sunken ship and Tom hits his head on the Window. An anchor also comes down on Tom's head. Jerry escapes and while swimming hits a sword fish. The sword fish becomes angry and tries to hit Jerry. Jerry escapes and comes face to face with Tom. Tom tries to hit him with a shovel but instead hits the sword fish. He damages the sword like nose of the fish. The swordfish becomes angry, Tom straightens the nose with a shovel.
Tom runs away and hides in a barrel. Jerry takes advantage of the situation and draws a red circle on the hole of the barrel. The swordfish hits through the hole and Tom comes out screaming. Tom stands behind a pole, the fish hits the pole and Tom hammers his nose on the side. Tom takes a sign of relief He now looks for Jerry. Jerry hides inside a divers head helmet while a sleeping octopus looks at them. Jerry tip toes from the door of the helmet while Tom watches. Tom catches Jerry while Octopus catches Tom. Jerry comes back for Tom's help.
All the time, Tom was dreaming and when wakes up, he becomes friends with Jerry.