San Francisco fashion designer Hannah Harvey (
Mary Martin) has been widowed for twenty years and nicknamed "Helpful Hannah", due to her penchant for persuading those around her to follow their bliss by expressing their creativity. She is reunited with twelve-years-widowed longtime friend Jarvis Holden (
Max Showalter), whose son Kent (
Timothy Patrick Murphy) loves to play the piano and is studying to take the real estate exam. Her efforts, to help Kent use his musical talent, clash with Jarvis' paternal intentions. Interior design student Dee Dee Draper (
Judy Landers) is working as a maid for Gregory King (
Ben Murphy), whose sometime-girlfriend Meredith Bradshaw (
Caren Kaye) is in love with someone else and fails to show up at boarding time. So Dee Dee, who is romantically attracted to Greg, takes Meredith's place on the cruise to spend time with him. But then Meredith arrives. Gopher (
Fred Grandy) takes a course in CPR and persuades Merrill (
Gavin MacLeod) to offer the course on board because it may save a life. Mr. Fenley (
Milton Berle) has retired and left his plumbing business to his son Dwaine (
Steven Keats) but feels that Dwaine is not working hard enough to keep the business going. Dwaine's wife Lily (
Andrea Howard) referees their constant arguments, which may ruin the cruise for all three of them.
—Maisie Fleckum