During World War II, the U.S. Navy's submarine service suffered the highest casualty percentage of all the American armed forces, losing one in five submariners. But despite the odds, these underwater warriors accounted for almost 60 percent of Japanese shipping losses, and were a major factor in winning the war. 16 U.S. submarines - and one German U-Boat - that saw action during WWII are now open to the public. Most have been restored...