Magnum, P.I. (1980): Season 4, Episode 1

4 - 1: Home from the Sea

Magnum's tradition of spending the Fourth of July alone at sea turns to a life-and-death battle when his surf ski capsizes from a reckless boater and a strong current takes him further and further from land. Forced to tread water for hours in shark-infested waters, Thomas uses his memories of his mom and dad to keep himself alive while Higgins, T.C., and Rick begin a frantic search for him.