The story was based on a real-life incident that occurred in 1941 on the Hebridean island of Eriskay when the SS Politician ran aground. The tale of how a group of local Scottish islanders raided a shipwreck for its consignment of 24,000 cases of whisky quickly became legend. What's less well reported, however, was the fact that the ship was also carrying a sizeable amount of hard cash. According to official files recently released by the Home Office, there was nearly 290,000 ten shilling notes on board as well (this would be the equivalent of several million pounds at today's prices), not all of which was ever recovered.
American censors insisted on a coda being inserted at the end of the film, stating that the stolen whisky brought nothing but unhappiness to the islanders, even though quite the opposite was true in real life.
In the original novel, the island was populated with both Catholics and Calvinists. The Catholics were dropped from the film as they would have had no trouble with not observing the Sabbath to salvage the whisky-laden ship.
Part of the film's appeal to British audiences in the late '40s was that wartime rationing was still in place and times were very austere. The film's flaunting attitude towards authority obviously struck a chord.
The first Ealing comedy to achieve some measure of box office success in the USA. It was followed within 12 months by Passport to Pimlico (1949) and Kind Hearts and Coronets (1949), quickly establishing Ealing as a leading light of comedy films.
The main reason for the film going dramatically so over budget was not director Alexander Mackendrick's inexperience (this was his first film) but the appalling weather that the production had to endure, 1948's summer being one of the worst on record.
Fourteen whisky bottles, said to be the last surviving from the wreck of the SS Politician, the real-life shipwreck that inspired the film, were sold in 1993 at a Glasgow auction for £12,012 (approximately $22,500 at 2006 conversion rates), with a bottle of Haig Dimple fetching £1,210 (the equivalent of $2,270).
Producer Michael Balcon was a bit thrown when a visiting American film executive saw the film and described it as a 'sleeper'. A term not known to Balcon at the time, he thought the executive meant it would put the audience to sleep.
The author of the original novel, Compton MacKenzie, plays the captain of the ship that runs aground on the island. In reality, Mackenzie took great exception to the number of takes that director Alexander Mackendrick made him do.