When filming began, Robert Mitchum worried that Deborah Kerr would be like the prim characters she frequently played. However, after she swore at director John Huston during one take, Mitchum, who was in the water, almost drowned laughing. The two stars went on to have an enduring friendship which lasted until Mitchum's death in 1997.
The script called for several Japanese-speaking officers and a company of Japanese troops to be on the island. There were no Japanese men on the islands of Trinidad and Tobago, where the film was shot. A half-dozen who spoke the language finally were found in a Japanese emigrant community in Brazil and flown to the location to play the officers. For the non-speaking roles of Japanese troops, the company hired 50 Chinese who worked in the island's restaurants and laundries. This caused friction with the local islanders, who found it difficult, if not impossible, to get their clothes cleaned or to get a meal in a restaurant because most of the employees were working on the film.
After spending so much time in Trinidad/Tobago, Robert Mitchum became enamored with Calypso music, so much so that he recorded an album called "Calypso - Is Like So", and was released on Capitol Records. It features him doing spot-on imitations of the style and is still available on CD.
Robert Mitchum had just returned from spending four months in Tobago on Fire Down Below (1957) with Jack Lemmon and Rita Hayworth when he learned that his agent had committed him to this movie, filming in Tobago.