Guest stars include Georgia Engel as a stowaway, Gary Frank and Melanie Mayron as a pair of tremulous honeymooners, Stella Stevens and Pat Harrington as an eternally bickering married couple, and Audra Lindley and Phil Silvers as respectively, an outspoken middle-aged lady and a woebegone widower.
A sportswriter (Bill Bixby) romances a paraplegic former tennis pro (Brenda Benet), and they may have been a couple prior; Doc falls for a seasick stowaway (Charo) who creates havoc; A practical joker (Milton Berle) plays one joke too many and learns a lesson.
Guest Stars: Scatman Crothers as Virgil 'Scattergun' Gibson, Graham Jarvis as Waldo Linden, Vicki Lawrence as Robin Brandt, Dick Van Patten as Congressman John Whitcomb, Maureen McCormick as Suzy Corbett, Bobby Sherman as Rick Leonard, and Vernee Watson-Johnson as Stephanie Hayden (credited as Vernée Watson).
Guest Stars: Frank Converse as Bill Thompson, Marcia Strassman as Stephanie Lewis, Pat Crowley as Noreen Badger, Marion Ross as Rose Higby, Brett Halsey as Clark Tyler, and Peter Isacksen as L. Courtney Stubing IV.
An illusionist is in such demand that he nearly misses what is in front of him; two recently reunited parents have trouble trying to stop their son from telling tall tales; Julie's model friend, scarred physically and psychologically by a car crash, is romanced by Gopher and Doc but is suspicious of their motives.
A minister falls for a Las Vegas exotic dancer, much to the dismay of a female parishioner, who attempts to break them up but causes a strain on her marriage; a man tries to help his wife overcome her denial over her blindness; the crew convinces the chief engineer to forgo his Thanksgiving holiday by having his entire family stow away on board the ship.
A vacationing chauffeur and his wealthy employer fall in love; a famous model causes love-smitten Gopher to fantasize that he is various flamboyant heroes; a separated couple vies for their son's affection; Reggie Jackson (as himself) can't convince anyone on board that he is who he says he is.
A rocker meets and falls in love with a deaf girl; a gambler in marital trouble gets Doc to tell his wife how he feels; Isaac mistakes a conversation by two writers about an upcoming mystery-murder novel as an actual plot to kill the captain.
A 12-year-old resents the romance between his mother (Jessica Walter) and his teacher (Richard Gautier); a financially troubled man (Sonny Bono) finds $2,000 in a borrowed coat; Doc and his ex-wife (Juliet Prowse) realize they're still married.
A singer (Donny Osmond) is ashamed of his family, who arouses the curiosity of a novelist; two passengers (Robert Guillaume, Pam Grier) cheat on their mates; Captain Stubing invites the crew into his suite when their quarters are flooded.
Gopher's widowed mother (Ethel Merman) tries to hide her grief from her son; a comic (Johnny Yune) falls for a reporter (Momo Yashima) doing a story on him; a waiter (Nicholas Hammond) pretends to be a banker to win over a jet-setter (Hayley Mills).
The crew tries to impress a social worker (Lois Nettleton) aboard to determine if Stubing is a good parent; a mobster leader's (Frank Campanella) daughter and her husband (Eve Plumb, Sal Viscuso) honeymoon in the shadow of two bodyguards (Norman Alden, Richard Bakalyan); Isaac suspects a free-spending bank guard (Noah Beery Jr.) who is traveling with his wife (Alice Faye).
A model (BernNadette Stanis) uses Isaac to make her husband (Clifton Davis) jealous; a lawyer (David Hasselhoff) wants to marry a colleague (Shelley Fabares) who is afraid to commit due to the ten-year difference in their ages; a woman (Peggy Cass) thinks a carefree attitude will save her marriage from boredom.
In the Virgin Islands, a wine-tasting competition is held, and Julie's aunt helps her friend scheme to snag the contest's wealthy sponsor; a judge starts a shipboard fling without getting to know his new partner well; a married couple who gets divorced every year for tax purposes takes the cruise; Vicki pines over a pro football player.
A teacher tries to hide his side job as a male stripper from a PTA member; Isaac's advice leads a husband astray, and his attempts to fix the problem only make matters worse; the captain suspects a known burglar in a theft of expensive jewels.
A man seeks revenge on his brother, "Dr. Adam Bricker"; an elderly couple evicted from their home tries to scam a free cruise; a plain woman meets the suave author of the trashy romance novel she is reading (called Passion at Dawn).
Doc weds a concert cellist but finds she didn't marry him for love; an overly cautious safety inspector learns it may be too risky to play it safe; a high-strung executive falls for his female vice president.
Guest stars: Priscilla Barnes as Swedish masseuse/trainer Brittany Sorenson, Douglas Barr as Dave Pursinger, Sonny Bono as Steve Bloom, Tom Bosley as Harry Meacham, Woody Brown as Trig Norquist, Mary Crosby as Megan Lewis, John James as Dr.
Isaac avoids a physical exam to hide a congenital condition that could jeopardize his job, while the nurse develops a crush on him; a young woman's older boyfriend turns out to be her mother's former lover; Julie's cousin wants to dump his fiancée.
The crew is in Greece working a cruise a college is having its graduation ceremony aboard: Guest stars: Leigh McCloskey, William R. Moses After being let go by her employer, April Lopez (Charo) plans to move back home to Mexico.
Aboard a country music jamboree cruise: Guest stars: Misty Rowe A woman suffering from end stage heart failure and a man wanted in the U.S. for killing a drug dealer to protect his students begin a romance.
Guest stars: Cathryn Damon, Florence Henderson, Gordon Jump, Kim Lankford, Robert Reed, Deborah Shelton, Clint Walker On a Japanese junket, a teacher impersonates a geisha to stay near the Captain; lottery winners carry their rags-to-riches routine to comic heights; a girl and her mother fall in love with two strangers.
Guest stars: Kirstie Alley, Danielle Brisebois, William Christopher, David Doyle, Dan Haggerty, Cindy Hayes, Elaine Joyce, Parker Stevenson A woman (Markie Post), who is being sought by a private detective (Don Gordon) to testify in a messy divorce case, sneaks on board disguised as a young girl.
A retired actress (Claire Trevor) seeks help from her son-in-law (James Houghton) in effecting a reconciliation with her daughter (Morgan Brittany); a widowed passenger (Arlene Dahl) has a shipboard romance with the ship's engineer (Vic Tayback); two newlyweds (Delta Burke and Lou Richards) cause havoc as the husband is convinced the world is coming to an end.
Guest stars: Barnard Hughes as Joseph Stobble, Dean Paul Martin as Brad Elliott, Ted McGinley as Ashley 'Ace' Covington Evans, Lee Meriwether as Jessica Chapman-Elliott, Michael Spound as Larry Chapman, and Carlene Watkins as Mrs. Susan Russell.
A ship's maid (Luise Rainer) has resented her twin sister for decades; Barry (Kin Shriner) and Sheila (Jenilee Harrison) take a scientific approach to conception; Isaac and blind Darnell (LaVar Burton) compete for Terry Cook (Shari Belafonte).
Judy thinks a writer (Ben Murphy) of children's books is perfect for her picky cousin (Ellen Bry), who is also pregnant; A pro wrestler (Tim Rossovich) forbids his sister (Jennifer Holmes) to associate with his opponent (Bruce Jenner); Gopher is accidentally hypnotized and given a post-hypnotic suggestion that he's the captain.
Cruising the Nile – the Captain and his friend's widow (Jean Stapleton) share memories; A producer (John Astin) wants a starlet (Deborah Adair) to play Cleopatra; A woman (Catherine Oxenberg) eyes the gold ankh that Doc was given at a bazaar; A busy man (James Sloyan) may lose his schoolteacher wife (Valerie Harper) to a former student.
Spain cruise: The grandson (Lorenzo Lamas) of a famous matador (Cesar Romero) wants to write rather than become a bullfighter; A woman (Sada Thompson), who spent 20 years in prison, hopes to be reunited with her daughter (Melissa Sue Anderson); A passenger (Adrian Zmed) is seeing both Judy and Vicki without their knowledge; Isaac helps a pregnant unmarried stowaway (Olivia Brown).
Guest Stars: Marion Ross as Emily Stubing, Lloyd Bochner as George Tillman, Arlene Dahl as Jessica York, Peter Graves as Leonard Culver, Julie Harris as Irene Culver, Jenilee Harrison as Sarah York, Roger E. Mosley as Jeffrey T. Gilbert, John Rubinstein as Allan Davis, Connie Stevens as Margret Grant, Alan Thicke as Robert McBride, Jayne Meadows as Jayne Meadows (credited as Jayne Meadows Allen), Steve Allen as Steve Allen, Army Archerd as himself, Selma Archerd as Selma Archerd, Barbi Benton as Barbi Benton, Milton Berle as himself, Barbara Billingsley as June Cleaver, Tom Bosley as Howard Pfister, Ruth Buzzi as Ruth Buzzi, Carol Channing as Tante Sylvia, Charo as April Lopez, Bert Convy as Bert Convy (credited as Bert Convey), Elinor Donahue as Betty Anderson, Tony Dow as Wally Cleaver, Florence Henderson as Carol Brady, Gordon Jump as Maître d, Don Knotts as Don Knotts, Judy Landers as Judy Landers, Tina Louise as Tina Louise, Patti MacLeod as Patti MacLeod, Robert Mandan Robert Mandan, Jerry Mathers as Beaver Cleaver, Christopher Norris as herself, Louis Nye as Louis Nye, Tom Poston as Tom Poston, Juliet Prowse as Juliet Prowse, Robert Reed as Mike Brady, Charles Siebert as Dr. Stanley Riverside, Gale Storm as Gale Storm, Vic Tayback as Vic Tayback, Charlene Tilton as Secretary, Leslie Uggams as Leslie Uggams, Jo Anne Worley as Jo Anne Worley, and Jane Wyatt as Margaret Anderson.