Maverick - Season 3 - Eps 17: Cruise of the Cynthia B.
Bret is one of the seven owners of a Riverboat who start down the Mississippi for Memphis to sell the broken-down craft, but soon in a deadly game of 10 Little Indians one owner after another is found mysteriously dead. It becomes apparent that if the boat does reach Memphis, it's almost certain it will have but one owner.
About Maverick

Title: Maverick
First Air Date: 1957-09-22
Last Air Date: 1962-04-22
Status: Ended
Rating: 6.8/10 (from 37 votes)
Language: EN
Seasons: 5
Total Episodes: 124
Network: ABC
Genres: Comedy, Western
Production Companies: Warner Bros. Television
Synopsis
The Maverick boys - Bret, Bart, Beau and Brent - are a clan of well-dressed dandies, gamblers who'd much rather make their money playing cards than messing up their fine clothing with actual work. Sly and clever, none of the Mavericks are much for acts of derring do, but they can be courageous when the situation calls for it. Most often, however, they live by their wits and considerable charm.
Cast

Jack Kelly
Bart Maverick