The harsh conditions of the shoot took its toll: actors and actresses were soaked with water and oil, which led to two cases of pneumonia for Tallulah Bankhead, an illness for Mary Anderson, and two cracked ribs for Hume Cronyn according to his autobiography. Production was temporarily halted twice to allow for recovery of the cast.
When Rittenhouse referred to Joe as George, Joe said that he preferred to be called by his real name. George was a standard nickname for all black attendants, originating from the black servants on the Pullman passenger trains who were called George after the owner George Pullman.
This movie was shot entirely on a restricted set in which the boat was secured in a large studio tank. Sir Alfred Hitchcock, always striving for realism, insisted that the boat never remain stationary and that there always be an added touch of ocean mist and fog compounded of oil forced through dry ice.
Asked why he had decided not to have any musical score during the narrative of this movie, Alfred Hitchcock reasoned that the audience wouldn't know where the music was coming from in the middle of an ocean. Composer David Raskin replied "Ask Mr. Hitchcock to explain where the camera came from and I'll tell him where the music comes from."
After she caught pneumonia, Tallulah Bankhead was given a puppy by Sir Alfred Hitchcock for being such a good sport during the movie. He had already named the dog Hitchcock.
Alfred Hitchcock: In "before" and "after" pictures in a newspaper advertisement for Reduco Obesity Slayer. The pictures were genuine, as he had just been on a crash diet (although not with the fictional Reduco) dropping from three hundred to two hundred pounds. However, the so-called "Reduco Obesity Slayer" diet pill or potion ad seemed so real that people who had seen the movie called the studio and wrote letters to Hitchcock asking where could they get this product. (In Rope (1948), a neon sign advertising "Reduco" with Hitchcock's famous silhouette is seen outside the Manhattan apartment where the movie takes place.)