The Sharkfighters plot
"FIGHTING THE TERROR OF THE SEAS!"
Lieutenant Ben Staves arrives on a small island not far from Havana, where he joins a Navy science project. They are trying to develop an effective shark repellent to save the lives of military personnel stranded in shark-infested waters. Having lost many crew members to sharks after his ship was sunk by the Japanese, he is very driven to make the project a success. Against the advice of others, he demands that the drug be tested on a living person surrounded by hungry sharks. He appoints no one but himself as the test subject.