Key figures in "The Aquanauts" are an adventurous young diver, Drake Andres, and his equally spirited assistant, Larry Lahr, , who continually find themselves involved in numerous intrigues and complications arising from the natural hazards of their occupation. In the premiere episode, Andrews and Lahr take on an assignment for a mining company in shark-infested waters off Hawaii. The assignment: locate manganese underwater. Andrews soon learns that a cocky member of his diving team, Tyler Stack (Larry Pennell) is much more of a danger than the sharks. Andrews first meets Stack when Stack endangers the life of a girl whom he attempts to rescue after she has been stunned by an underwater explosion. Andrews then rescues the girl, named Doris (Sarah Marshall).
—Jorge Reinaldo Galindo Porras