Sea Wife (1957)

In 1942, a cargo ship jammed with British evacuees from Singapore is sunk by a Japanese sub. A small lifeboat carries a beautiful woman, an army officer, a bigoted administrator, and a black seaman. Only the seaman knows the woman is a nun. The men reveal their true selves under the hardships of survival. Told in a too-long flashback frame.

Unfortunately the movie Sea Wife is not yet available on HBO Max.