V.I.Ps at the Pentagon are questioning the value of P.T. boats to the war effort, so Admiral Reynolds orders a Combat Photographer to Taratupa, to film a P.T. crew in action. The Photographer – A bumbling, rather mousy Seaman by the name of Sweeney (Arte Johnson) – Soon arrives, for the assignment. But Gruber (Carl Ballatine) – Seeing an opportunity to make some fast cash – Cons Sweeney out of his movie camera, so he can shoot movies of the Taratupa Sailors, to send home to their families. But his little enterprise is interrupted by an order to head out on a battle mission. Gruber sneaks the camera back, and battle-shy Sweeney manages to film the 73 crew sinking a Japanese P.T. boat, about which, Captain Binghamton is very pleased. But, upon viewing the film, that evening, McHale and the crew find that Sweeney's footage is double-exposed onto Gruber's home movies. McHale is, of course, livid, but the crew brainstorms, and McHale soon comes up with the idea of staging a phony battle, so that they can save Sweeney's neck, as well as their own. The 73 is quickly made up to look like a Jap P.T. boat, complete with flag and markings, and Parker, Happy, Tinker, and Gruber don some of Gruber's souvenir Jap uniforms. They then head out, so that Sweeney can get his footage. But, trouble soon begins. An American fighter plane spots and strafes them, causing them to run for the cover of a nearby island, and a stray bullet damages the 73's engines, putting them temporarily out of commission. Then, they get a break, when a Japanese submarine shows up. When the Jap sub crew sees the Jap flag, and Parker and the others in Jap uniforms, the Japs feel they are safe. Tinker gets the engines going again, and the crew goes to battle stations, as McHale heads the 73 toward the sub. They engage in some real combat action, saving Sweeney's neck, as well as their own.