One of twenty-six ships in the Military Sealift Command's Special Mission Ships Program, Zeus's primary mission was to support the Sound Surveillance System (SOSUS) that was renamed a year after the ship's commissioning as the Integrated Undersea Surveillance System (IUSS) in 1985. The ship's function was to transport, deploy, retrieve and repair submarine cables and test underwater sound devices, with a secondary mission of conducting acoustic, hydrographic, and bathymetric surveys