In 1947 Emeric Pressburger met the head of the script department at Paramount, who told him that the studio used this film as an example of the perfect screenplay, and was shown to writers stuck for inspiration or who needed a lesson in screenwriting.
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.
Michael Powell wanted to make A Matter of Life and Death (1946) at this time, but had to wait for access to Technicolor cameras. Those cameras were only rented to filmmakers and most remained in the U.S.A. during World War Two.
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. Mason has always contended that it was Michael Powell's reluctance to pay the expenses of Mason's wife on the location shoot.