There was a Camano Class light cargo ship U.S.S. Ryer (AG-138). It was originally delivered to the Army near the end of World War II, for coastal operations. The Ryer participated in the Korean War. Interestingly, the Ryer was sold in 1962 and the name was changed to the Ahti. The Ryer bears a very strong resemblance to the ship used in the making of this film. And may in fact be that ship, rented to make this film.
The name of the ship in the movie is the Ahti, a cargo ship of Finnish registry.
The Korean prisoner, Kim, was portrayed by Pancho Magalona, a well-known Filipino actor from the 1940s to the 1970s.