'Margot FitzSimons', who played Bridie in the film, is screen legend Maureen O'Hara's younger sister.
Michael Powell wanted to make Stairway to Heaven at this time but had to wait for access to Technicolor cameras.
Michael Powell's golden cocker spaniels Erik and Spangle make their third appearance on film when Joan goes to visit Mr. & Mrs. Robinson.
Roger Livesey was starring in a West End play at the time, so he could never go on location to Scotland. All his scenes were shot in the studio.
Roger Livesey was told that he was too old and too portly to play Torquil. Livesey soon managed to lose 20 pounds and altered his appearance to play the young Lieutenant.
James Mason was originally cast as Torquil but declined when told he would have to "live rough" in the islands. Ironically Roger Livesey never went to the islands because he was in a West End show at the time. A double was used for long shots and all close ups are shot in the studio.
C.W.R. Knight was a real life falconer and trained the golden eagle "Torquil" in this film.
Cinematographer Erwin Hillier never used a light meter during the shooting of this movie.
Corryvreckan is the second (or third, depending upon the source) largest whirlpool in the world. It forms in the Gulf (or Strait ) of Corryvreckan, a narrow strait located between the islands of Jura and Scarba, off the western Scottish coast. During a flood tide, the natural topography of the area, in conjunction with the strong water current, creates whirlpools, standing waves and other effects on the sea's surface.
In 1947 Emeric Pressburger met the head of the script department at Paramount who told Emeric that they used 'I Know Where I'm Going!' as an example of the perfect screenplay which was shown to any writers stuck for inspiration or who needed a lesson in screen writing.
John Laurie and Duncan McIntyre, who play the sons of Herbert Lomas and John Rae, respectively, were only ten and eleven years younger, respectively, than their supposed fathers.
The art department spent £40,000 - mainly on the tank and the whirlpool.