181106-N-ME396-012 GROTON, Conn. (Nov. 6, 2018) Machinist's Mate (Auxiliary) 2nd Class Alex Dorr operates the Multipurpose Reconfigurable Training System 3D (MRTS 3D) at Naval Submarine School. MRTS 3D is an advanced virtual reality simulation of the diesel auxiliary system aboard a modern American submarine designed to give Sailors a hands-on training experience handling equipment. (U.S. Navy photo by Mass Communication Specialist 3rd Class Tristan B. Lotz/Released)