When people think of naval warfare in the Pacific during World War II, they picture submarine captains locking onto targets, launching their torpedoes, and sending enemy ships to the bottom in a column of smoke and steel. That image, as dramatic as it may be, wasn’t always the truth. At least not early in the war. For nearly two years, American submariners went into battle with a torpedo that refused to do its job. It wasn’t the enemy that nearly broke their spirits. It was the Mark 14.

On July 24, 1943, the submarine USS Tinosa SS-283 faced a golden opportunity and watched it slip away as torpedo after torpedo failed to explode.