After an African American boot-black called Oscar, who worked on the Paramount lot was cast in a bit part, a black cinema in Los Angeles billed this movie as: "Sensational star in Gambling Ship, Oscar supported by Cary Grant." All the promo pictures outside the cinema were of Oscar.
Cary Grant's character aggressively rubs the head of a railroad porter, who flinches. No words are exchanged. Audiences of the time knew what was happening. Sometimes a joke, sometimes a superstition, but a white man rubbing the head of a black boy or man (who at the time was referred to as a "boy") brought "good luck." African-Americans considered the practice repellent; but in the case of the porter who couldn't argue with passengers and needed their tips, there was nothing he could do. Sociologists describe the gesture as a master-servant practice where a white man assumes the right to do whatever he wants with any random black person.
A technical advisor was used to familiarize the actors in the film with the details of the parlance, activities, and manners of the gambling world.
One of over 700 Paramount productions, filmed between 1929 and 1949, which were sold to MCA/Universal in 1958 for television distribution, and have been owned and controlled by Universal ever since. Its initial television presentation took place in Omaha Friday 23 January 1959 on KETV (Channel 7); it later aired in Denver 17 July 1959 on KBTV (Channel 9), in New York City 9 November 1959 on the Late, Late Show on WCBS (Channel 2), in Philadelphia 18 January 1960 on WCAU (Channel 10), in Grand Rapids 19 February 1960 on WOOD (Channel 8), in Detroit 15 September 1960 on WJBK (Channel 2), in Phoenix 16 September 1960 on KVAR (Channel 12), in Chicago 16 October 1960 on WBBM (Channel 2), and, finally, in Los Angeles 25 November 1960 on KNXT (Channel 2). It was released on DVD 19 April 2016 as one of 18 [Paramount] titles in Universal's Cary Grant: The Vault Collection, and again 12 October 2016 as part of the Universal Vault Series.
An interesting predecessor to "Mr. Lucky" (1943), in which Cary Grant also played a gambling ship operator.