When director Jonathan visited the World War II submarine exhibition on 1992, he came up with the idea of filming the submarine war in World War II. Within three years, he traveled around the world, exploring "retired" World War II submarines, ships and museums, interviewing veterans, and reading World War II books, submarine diaries and battle diaries.
1: 1 Build submarines in standard size.
In order to be realistic, the director invited two landscape experts to build a small German submarine and an American S-submarine during World War II. However, because there are few photos of the S-type submarine and the military unit refuses to disclose the internal structure diagram on the grounds of safety, the plan to rebuild the American submarine is facing a crisis. Fortunately, with the help of Hanifin, a senior naval officer, the S-submarine reappeared on the screen. The internal models of the two submarines are made according to the standard size of 1∶ 1, and the internal structure is the same as that of that year. Among them, U57 1 weighs 600 tons, and it is copied and reduced on the general steering system. This system allows submarines to move up and down at any angle, sink and sail in the sea. It surprised an officer who fought on this submarine that year, as if he had returned to the year of World War II.
In order to make the submarine's effect more realistic, five 50-foot-long submarine models were completed. Each model has different functions, some can advance, some can dive, and some can launch torpedoes. It is enough to show the real submarine's assault in the deep sea and its movement in the water.
Actors are collectively "abused"
During the filming, the actors' heads were bruised and swollen to varying degrees, all because of the perfectionism of Patrick Hannifin, the filming consultant, who "did whatever it took to be realistic". Patrick Hannifin used to operate Nazi German submarines. He said that the submarine space at that time was "very narrow." If the director and producer are determined to simulate the real situation at that time and spend huge sums of money to build Nazi submarines in equal proportions, the film will be credible. Because these actors were burly, and the submarine officers at that time had strict height requirements to save personal space. The director asked the actors to run quickly in the narrow cabin and quickly through the narrow gate. With a little hesitation, these tall actors can understand what "a head bump" means. There is always endless water in the bilge, and the director always tells unskilled people to start over and over again. After filming for a whole day, the bruises on my body can't be lost to martial arts stars. Only Harvey Kaituo, who plays the sergeant major, is as fast and relaxed as flying. Others think that he is "old-fashioned", but he smiles and admits that he graduated from the Naval Academy and has long been well trained.
Hannifin said that submarines at that time would often leak water if they were not well designed today. So the director followed suit and pushed the hose to the top of his head. The actors were all wet, but they also fell down one after another because of the wet ground. In particular, when the submarine encountered a mine explosion, the hull shook violently up and down, left and right, and everyone was shocked. Take turns to perform "Dogs eat shit".
Be criticized for tampering with history
After the film was released, historians pointed out that the film seriously falsified the historical facts: the special cipher machine invented by Germany in World War II mentioned in the film was not first captured by American submarines, but was first acquired by British submarines in August of 194 1. It was not until 1944 that the US military intercepted another one. Based on this, under the pressure of British submarine officers and soldiers, the film reluctantly added notes to the subtitles.