USS Altair (AD-11) was the leading vessel of a class of three United States Navy destroyer tenders, commissioned from 1921 to 1946 and notable for its extensive service during World War II. Originally laid down as the steel-hulled cargo ship SS Edisto under a US Shipping Board contract on December 18, 1918, in Seattle by Skinner & Eddy, she was launched on May 10, 1919. After a brief operation under the US Shipping Board, Edisto was transferred to the Navy in October 1921, renamed USS Altair (AD-11), and commissioned in December 1921. She was converted into a destroyer tender at the New York Navy Yard, a process completed by late November 1922, involving the installation of surplus machine tools and shop equipment from dismantled military plants. Altair’s primary role was to support destroyer squadrons, providing repairs, maintenance, and logistical support. From 1922 to 1939, she operated along the U.S. West Coast, including Hawaiian waters, and participated in notable activities such as joint maneuvers and troop transports, including a 1927 Marine expedition to Nicaragua. During the late 1930s and early 1940s, she was based at Pearl Harbor, serving as a tender for destroyers and acting as a plane guard for flying boats. With the advent of World War II, Altair was relocated to Bermuda, supporting Atlantic Fleet destroyers on the Neutrality Patrol. Following the U.S. entry into the war after Pearl Harbor, she continued tender operations at Trinidad, Bermuda, and Cuba, providing vital maintenance services for Atlantic destroyers and escorts. In 1945, she was briefly prepared for Pacific service but arrived in Hawaii just before the war ended. After hostilities ceased, she supported small ships at Pearl Harbor until May 1946, when she was decommissioned at Mare Island. Altair was transferred to the Maritime Commission and subsequently scrapped in 1948. Her service highlights her importance as a support vessel in both peacetime and wartime, contributing significantly to fleet readiness across the Pacific and Atlantic theaters.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.