ROBERT SHAW as QUINT
The demise of the heavy cruiser U. S. S. Indianapolis is a true story. It led a long and honored career from 1932 until July 30, 1945. Its last mission on July 26, 1945 was TOP SECRET. On that day, the Indianapolis successfully delivered to Tinian Island, the critical parts (the uranium projectile) for "Little-Boy," the atomic bomb that would be dropped on Hiroshima.
Four days later in the Philippine Sea, a Japanese submarine attacked. It is uncertain whether the cruiser was hit two or three times but from the first on-board explosion to the time she sank...was twelve minutes.
It is estimated that three hundred men died from the attack. 880 others abandoned ship and went into water. In a combination or being victims of circumstance and naval stupidity, the men were left to their own devices for four days.
The main reason they were left there was; the mission was so secret that against normal naval procedure...no notice was sent to the port of destination...that meant they weren't missing because nobody was expecting them. Plus there was radio silence. The Indianapolis sent out three distress calls any way. At first all of these S. O. S.'s were claimed to have never been received (later it was discovered that for various reasons, these calls were ignored).
For the sake of the movie's tension, Quint goes into some gory shark-related details about the four-day wait for rescue. Wikipedia takes a less Hollywood-ish tact, saying that the men were systematically dying from drowning, exposure and dehydration with the sharks feeding on the corpses.
Of the original 1196 crew members only 317 lived to tell the tale. Ironically, the Indianapolis was the last major war vessel lost in WWII.
The Indianapolis is just one of countless stories of the ultimate sacrifice. Please, never forget what it means to be an American and always take time to thank the veterans you come across...for their devotion to our freedom and way of life.