The operation of the submarine as shown in this movie was so accurate that the Navy used it as a training film during World War II.
The Copperfin submarine was an exact scale model of a real US Navy submarine. However, for reasons of military security, equipment and operating mechanisms were of varying kinds and varieties not found on US submarines so the enemy could not get an accurate picture of what the interior of a Navy submarine looked like.
The appendectomy operation conducted by the character Pills (William Prince) was inspired by an actual appendix operation performed aboard the submarine "Seadragon" in 1942. The real-life appendectomy was performed by 22-year-old pharmacist's mate Wheeler B. Lipes with the help of an assistant. The two were able to extract the appendix of Seaman Darrell Dean Rector under very trying conditions with limited resources and skills. They used kitchen utensils and equipment including a strainer and bent spoons as retractors; alcohol taken from torpedoes and sterilized pajamas as surgical gowns. The sub's crew had believed that Lipes was the most qualified person to perform such a life-or-death operation, as he had apparently observed appendectomies before. Lipes was persuaded to do the operation by his fellow crewmen. The operation took place 120 feet below the surface of the South China Sea. Afterward, Lipes' actions were criticized by US Navy doctors, and the US Surgeon General even considered court-martialling him. Over 60 years later, in April 2005, Lipes finally received the US Navy Commendation Medal, two months before his death. According to the 19 April 2005 Los Angeles Times obituary of Lipes, this operation was the first ever performed in a submerged submarine.
Two members of the real-life US Navy submarine Wahoo were consultants and technical advisers on this film, according to a story in the "New York Herald Tribune". They were crew member Andy Lennox and Lt. Cmdr. Dudley Walker Morton. As a way of saying "thank you" the chili and canned pumpkin used by "Cookie" is labeled as being made by "Lennox".