In the opening days of the war in the Pacific, the U.S. Submarine Force was abruptly thrust into a role of unexpected and frightening importance. At Pearl Harbor on December 7, 1941, torpedo planes and bombers from aircraft carriers of the Imperial Japanese Navy crippled the U.S. Pacific Fleet. Two days later Japanese bombers flattened the Cavite Naval Station in Manilla Bay, home of the U.S. Asiatic Fleet. These attacks doomed the Philippines and opened the door for Japanese conquests in the Southwest Pacific and Southeast Asia. It would be many months before the U.S. Navy could repair wounds and launch a major offensive.
For all practical purposes, the American submarines were now the only U.S. weapons capable of carrying the war to the enemy. In the entire Pacific there were just 55 submarines. One of these, USS SEALION, had already become the first U.S. submarine casualty of the war, having been sunk at her pier during the Japanese attack on Cavite. A dozen more were obsolete S-class boats, relics of the 1920's, lacking in range, firepower and underwater endurance. Yet this tiny, poorly equipped undersea force would carry the offensive to the enemy from the very start. And before they finished waging their deadly campaign, the U.S. submarines would write one of the greatest chapters in the history of naval warfare.
No American, and certainly no Japanese naval officer, could have imagined the extent of the retribution that the U.S. submarines would extract from Japan's Imperial Navy. In the course of the war American submarines would sink no fewer than 201 Japanese warships. Of vastly greater importance to the wars outcome, the submarines would send to the ocean's floor 1,113 Japanese merchant ships, for a staggering total of 4,779,902 tons. At the peak of their efficiency, U.S. submarines were sinking merchant ships at a rate that was three times faster than Japanese shipyards could turn them out.
Less than 2% of U.S. sailors served in submarines, yet submarines would sink 55% of all Japanese ships lost in World War II. More than the U.S. Navy's surface ships, its carrier planes, and the Army Air Force combined!
However, for its many vital achievements, the submarine service would pay a terrible price. Fifty two boats and over 3500 submariners, one out of every five, would fail to return. Officially they were listed as missing in action. "Over Due and Presumed Lost" was the epitaph for both men and boat. Theirs was the highest loss rate of any unit in the Navy. Today we speak of these men, our shipmates, as being on Eternal Patrol.