Meet the USS Montana: The U.S. Navy's Most Advanced Sub Ever? These latest submarines continue to inform the Navy’s expanded mission envelope for attack submarines, given their increased ability to conduct undersea reconnaissance. Here’s What You Need to Remember: The U.S. Navy has now launched the USS Montana, its final Block III Virginia-class attack submarine, a much-anticipated development intended to bring new levels of undersea warfare technology and mission possibilities to the Navy. The new boat set sail from Huntington Ingalls shipyard in Newport News, Va., on March 3. The Virginia Block III boats incorporate a handful of next-generation innovations to include a more capable, technically advanced Large Aperture Bow sonar array bringing new undersea surveillance and reconnaissance options to submarine commanders as well as “Lock Out Trunk” configuration to improve Special Operations forces mission transport. A Lock Out Trunk, which could be described as a specially engineered compartment enabling Navy SEALs to exit the boat for clandestine missions without the submarine needing to surface. Mine-detection, covert attacks and rescue missions as well as undersea scout missions are all safer and less detectable with Block III.