A former film director hires the aquanauts to help him retrieve a treasure-filled bathtub from the bottom of the sea. Spangler: Dan Tobin. Mike: Ron Ely. Larry: Jeremy Slate. Mavis: Florence Sundstrom. Paula: Kay Hughes. Ellie: Ann Hughes.
A routine investigation takes a serious turn when Mike and Larry uncover a counterfeiting operation. Max: John Dehner. Nancy: Donna Douglas. Oscar: Dabbs Greer. Horton: Ken Curtis. Mike: Ron Ely. Larry: Jeremy Slate. Buddy: L.Q. Jones.
Before he can enjoy his wealth, heir Wes Halley is kidnapped and held for ransom. Leo: Burt Reynolds. Halley: John Lupton. Judy: Nina Shipman. Mike: Ron Ely. Larry: Jeremy Slate. Wells: Joseph Hamilton.
Mike and Larry try to break up a dope-pushing racket that operates out of the aquanauts' store. Mike: Ron Ely. Larry: Jeremy Slate. Baylor: Ray Hamilton. Pappas: Norman Fell. Captain: Charles Thompson.
Mike and Larry launch a desperate search for the owner of a defective diving tank. Larry: Jeremy Slate. Mike: Ron Ely. June: June Blair. Wesson: William Bramley. Jacobs: John Fielder. Susan: Nora Hayden.
Elmer Burnside tries to lure Mike and Larry by lowering a jug of money into the water. Mike: Ron Ely. Larry: Jeremy Slate. Burnside: Ken Drake. Valerie: Erin O'Brien. Del: Charles Cooper. Chris: John Considine.
A seemingly routine task---recovering a trophy from a sunken boat---may prove deadly for Larry and Mike (Ron Ely). Dana: Mary Tyler Moore. Larry: Jeremy Slate. Corey: William Conrad. Sylvia: Audrey Dalton. Turrell: Arthur Hunnicutt. Garland: Ed Nelson.
Drake and Larry take a gamble to rescue a marine biologist trapped by an underwater landslide. Drake: Keith Larsen. Larry: Jeremy Slate. Ruth: Whitney Blake. Lisa: Gina Gillespie. Stan: Gregory Walcott.
Drake investigates a premature explosion that killed a member of his underwater mapping team. Drake: Keith Larsen. Larry: Jeremy Slate. Penfield: Robert Strauss. Gloria: Annelle Hayes. Dierkes: Ed Howell.
The aquanauts probe unusual air bubbles that rise to the ocean's surface. Carney: Brad Dexter. Jimmy: Burt Reynolds. Larry: Jeremy Slate. Gloria: Donna Douglas. Consuelo: Valerie Allen. Drake: Keith Larsen.