The ASDS is the first dry combat submersible designed to deliver navy seals and their combat gear clandestinely to hostile shores. Carried on the back of a nuclear submarine to the mission area, ASDS offers greater speed, endurance, depth, and stealth than current battery powered swimmer delivery vehicles. This sophisticated vehicle is equiped with multiple sonars , an inertial navagation system, a GPS satalite navagation reciver, and a robust communications suit. It is fitted with two hydraulically elevated masts, one that contains an optical periscope and ESM system and one with communications antennas. ASDS is piloted by a submarine qualified officer and is co-piloted by a seal officer. The first submarines capable of carrying the ASDS are the USS Charlotte, and the USS Greenville,.