USS Compass Island AG153

• USS Compass Island (AG-153) was a U.S. Navy vessel converted from the Liberty ship SS Garden Mariner to serve as a navigation system test ship. • The ship was launched in 1945 as a standard Liberty cargo ship before being acquired by the Navy in 1953 for conversion. • USS Compass Island played a crucial role in the development and testing of the Navy's Shipboard Inertial Navigation System (SINS), a technology critical for accurate submarine missile launches. • The ship's name, "Compass Island," refers to an island in the Hudson River, New York, fitting its navigation-focused mission. • In 1957, the USS Compass Island became the first ship in the world to operate using inertial navigation alone, without traditional celestial or radio aids. • The navigation systems tested aboard Compass Island were later used aboard the Navy’s Polaris ballistic missile submarines, helping to enable the U.S. strategic deterrence posture during the Cold War. • Many prominent Navy officers and scientists, including Dr. Charles Stark Draper, known as the "father of inertial navigation," worked closely on the Compass Island’s projects. • In addition to navigation testing, the ship also supported research on other advanced electronic systems, contributing to the Navy’s technological edge. • The USS Compass Island was decommissioned in 1968 after over a decade of service as a testbed for cutting-edge navigation technology. • After decommissioning, she was placed in the National Defense Reserve Fleet and later scrapped in 2003, closing the chapter on a vessel that quietly revolutionized naval navigation and strategic capabilities.