The Stern Door and Ramp is a closed watertight structure at the rear of the ship, designed with low radar cross-section stern doors and an associated stern ramp that provides positive buoyancy. The design includes a coaming seal around the periphery that excludes the ingress of water due to wake, wave slap, and spray. The door and the ramp are both hydraulically operated and electrically controlled and are designed to open or close within 60 seconds in up to Sea State 4 conditions. The main doors operate to a clear opening of approximately 4 meters with an opening range up to 180 degrees. The main ramp has a lift capacity of up to 10,250 kg with a bunk load of 2,000 kg, deploying downward from the decking with a 15-degree range of motion from stowed to fully deployed. The hydraulic system provides 2,500 psi hydraulic power for door and ramp operation, including the hydraulic power unit, control valves, and hydraulic cylinders.