Defenders of the Deep

Defenders of the Deep

Fun Fact: if it wasn’t for the clumsiness of the USS Tambor, the Battle of Midway might never have been won. (Schultz)

"Today under the vast and lonely waves, submariners stand to watch for America and the noble dream of freedom for all-so close to man's grasp” -Ernest M. Eller, Rear Admiral. The Pacific War, sometimes called the Asia-Pacific War, was the theater of World War II that was fought in the Pacific and East Asia. The Pacific War saw the Allied powers pitted against the Empire of Japan, who was briefly aided by Thailand and to a much lesser extent by its Axis allies, Germany and Italy. United States submarines played a major role in defeating Japan, even though submarines made up a small proportion of the Allied navies—less than two percent in the case of the U.S. Navy ("Submarine Warfare"). Japan was strangled by the sinking of its merchant fleet, through the interception of many means of transport, and the disruption of nearly all oil imports, which were essential to weapons production and military operations. In fact, by early 1945 Japanese oil supplies were so limited that its naval fleet was virtually stranded. Submarine warfare was instrumental in the Pacific War because of newly-developed tactics, knowledge acquired from earlier confrontations, U.S. Navy technology that was advanced for its time, and the submarine’s intrinsic ability to remain invisible.

Through the new tactical advantages they provided, submarines made themselves vital to the success of the United States. Surface vessels navigate across what amounts to a featureless two-dimensional plain, whereas submarines roam throughout a vast, three-dimensional column of water. Operating in three dimensions provided new tactical opportunities for submarine skippers that were unavailable to their surface equivalents. “Sea denial” (hindering or preventing stronger adversaries from using certain nautical expanses) quickly became the underlying strategy of the United States Navy. Over sixty percent of the Japanese merchant fleet was destroyed by U.S. submarines, crippling Japan's ability to supply its military forces. Allied submarines in the Pacific War destroyed more Japanese cargo than all other weapons combined (Friedman). Three hundred and fourteen submarines served in the U.S. Navy, of which nearly 260 were deployed to the Pacific. When the Japanese attacked Hawaii in December 1941, 111 boats were in commission; 203 submarines from the Gato, Balao, and Tench classes were commissioned during the war. (Submarine Warfare). During the war, fifty-two U.S. submarines were lost to all causes, with forty-eight directly due to hostilities. U.S. submarines sank 1,560 enemy vessels, a total of 5.3 million tons, approximately fifty-five percent of the total sunk (Naval History Division).

An understanding of the challenges of submarine warfare and how to avoid the traps set for submarines gave the United States submariners an advantage over the less experienced Japanese navy. The Japanese military claimed its defenses sank 468 Allied submarines during the war. In actuality, only forty-two American submarines were sunk in the Pacific due to hostile action (Naval History Division). The U.S. was able to apply the knowledge they gained during WWI, which was a vital experience that the Japanese did not possess. Understanding the strength of tidal currents, prevailing winds, the effects of exposure to wave action, the nature of the seabed and where an anchor will hold, and many other different factors are all vital to skippering a submarine (Office of Naval Intelligence).

As advancements in technology spread worldwide, submarines became formidable adversaries of the United States Navy. The submarine had its first success in the war on February 17, 1864, when the CSS Hunley and USS Housatonic skirmished on the outskirts of Charleston harbor. The CSS Hunley utilized a torpedo which was an explosive charge at the end of a spar that had to be rammed into the hostile warship (Naval History Division). As with the aircraft and tanks, the concept of an underwater vessel is centuries old. With the development of the electric engine, the internal combustion engine, and the screw propeller the submarine became a feasible naval vessel. Submarines became increasingly practical with advancements in technology that allowed for larger submarines that did not rely on humans and oars for propulsion.

During WWI, the German military adopted a policy of "unrestricted submarine warfare," in which U-boats (German submarines) actively sought out and engaged enemy merchant ships. This idea of "unrestricted submarine warfare," became a vital strategy in WWII. Submarines had been one of the only weapons the United States could use in the first two years of WWII that were capable of affecting Japanese trade routes. By the last year of the war, Japanese merchant ships had been forced from the open ocean by successful submarine attacks. The U.S. Pacific Fleet submarines were able to start attacking Japanese merchants while American battleships were still burning in Pearl Harbor, long before the U.S. Navy surface fleet entered western Pacific waters (Holmes).

The success of Allied submarines was largely due to their element of surprise because concealment is not only a submarine's chief method of defense but also the tactical edge they provide on the open ocean. Submariners go to extravagant lengths to stay concealed. If their presence is revealed for any reason, they severely compromise their defenses. Submarines utilize sonar (SOund Navigation And Ranging) to locate enemy ships. Submarines typically operate their sonar sets in "passive" mode as they listen for telltale sounds emanating from enemy boats. Once