United States Pacific Fleet - Composition of The Pacific Fleet in May 1941

Composition of The Pacific Fleet in May 1941

On 7 December, the Fleet consisted of the Battle Force, Scouting Force, Base Force, Amphibious Force (ComPhibPac), and the Submarine Force (COMSUBPAC). Also in Hawaii was the Fourteenth Naval District, commanded by Rear Admiral Claude C. Bloch.

The Battle Force consisted of Battleships, Battle Force, made up of three Battleship Divisions: Battleship Division 1 with USS Pennsylvania (BB-38) and USS Arizona (BB-39) with USS Nevada (BB-36); Battleship Division 2 with USS Tennessee (BB-43) and USS California (BB-44) with USS Oklahoma (BB-37); and USS Colorado (BB-45), USS Maryland (BB-46) and USS West Virginia (BB-48). These nine battleships were intended to counterbalance the ten battleships of the Imperial Japanese Navy. At the time of the attack on Pearl Harbor, USS Pennsylvania (BB-38) was in dry dock and USS Colorado (BB-45) was being refitted at Bremerton Navy Yard, Washington State. USS Arizona (BB-39) was mated with USS Nevada (BB-36) and USS Oklahoma (BB-37) at that time.

Other components of the Battle Force included Aircraft, Battle Force, with Carrier Division One and Carrier Division Two, plus Cruiser Divisions 4, 5, and 6, as well as Destroyers, Battle Force. The Scouting Force included Cruiser Division Three (USS Richmond (CL-9), USS Concord (CL-10), and USS Trenton (CL-11)) and Cruiser Division Nine and Submarines, Scouting Force.

The Amphibious Force was formally known as Commander, Amphibious Forces, Pacific Fleet (ComPhibPac). On 7 December 1941 the Amphibious Force comprised the Army's 3rd Infantry Division at Fort Lewis, under Army operational control, the 2nd Marine Division, the 2nd Marine Aircraft Wing, the 2nd Defense Battalion (see Marine defense battalions), and a depot. One of PhibPac's subordinate commands during World War II was Transports, Amphibious Force, Pacific Fleet, or TransPhibPac. The commander of TransPhibPac was known as ComTransPhibPac.

In December 1941, the fleet consisted of nine battleships, three aircraft carriers, 12 heavy cruisers, eight light cruisers, 50 destroyers, 33 submarines, and 100 patrol bombers. This was approximately the fleet's strength at the time of the Japanese attack on Pearl Harbor. That day, the Japanese Combined Fleet carried out the attack on Pearl Harbor, initiating World War II in the Pacific. The Pacific Fleet's Battle Line was virtually destroyed, forcing the U.S. Navy to rely primarily on aircraft carriers and submarines for many months afterward.

Subsequently Pacific Fleet engagements during World War II included the Battle of Guam, the Marshalls-Gilberts raids, the Doolittle Raid, the Solomon Islands campaign, the Battle of the Coral Sea, the Battle of Midway, the Battle of the Eastern Solomons, the Battle of the Santa Cruz Islands, the Battle of the Philippine Sea, the Gilbert and Marshall Islands campaign, the Battle of Leyte Gulf, and the Battle of Okinawa. More minor battles included the Battle of Dutch Harbor. The Submarine Force began a sustained campaign of commerce raiding against Japan's merchant marine, beginning the very first day of the war, which ultimately claimed 1,314 ships totalling about 5.3 million tons (by the imperfect postwar reckoning of the Joint Army-Navy Assessment Committee, JANAC).

The West Loch disaster occurred at Pearl Harbor on 21 May 1944.