TC is returning from Molokai when he encounters engine problems and crashes into the water just before landing.
- Tom Selleck as Thomas Sullivan Magnum IV
- John Hillerman as Jonathan Quayle Higgins III
- Roger E. Mosley as Theodore "T.C." Calvin
- Larry Manetti as Rick Wright
- Glenn Cannon as Dr. Ibold
- Richard Lawson as Gerald Calvin
- Sam Vlahos as Leo
- James Grant Benton as Dave
- Rodney Philip Aiu as Carl (as Rod Aiu)
- Michael Dennis as Harry Bates (as Michael Norton-Dennis)
- Josie Over as Desk Clerk at the Lahaina Hotel
- Stephen Landis as Jack Phillips (as Steve Landis)
- Sylvia S. McAlester as Nora Phillips
- Judith Sykes as Maid (as Judy Sykes)
- Larry Goeas as Security Guard
- The opening preview contains a very unusual edit of the regular theme music, effectively starting near the end, and then cutting into another piece of music.
- The "Lahaina Hotel" is fictional. No scenes were actually filmed in Lahaina, or anywhere else on Maui for that matter.
- Castle Memorial Hospital in Kailua is used as a filming location.
- Josie Over (Hotel Desk Clerk) makes her first of four appearances on the show. A local actress, Josie has appeared in over a dozen episodes of Hawaii Five-O and will later appear in a handful of episodes in another popular TV show filmed in Oahu, Jake and the Fatman (1987-1992).
- Higgins: ...T.C. is indeed a man of exemplary character.
- Rick: You alright, buddy?
- Magnum: Yeah.
- Rick: What went on down there? A shark?
- Magnum: The only shark was him.
- Rick: Who, T.C.'s brother?
- Magnum: Somehow I don't think he was a relation.