The low-current NAC-2 autopilot computer is ideal for smaller vessels, designed to run small hydraulic drives and mechanical drives for vessels up to 10 meters (33 feet) in length. Also provides solenoid output. The low-current NAC-2 autopilot computer is ideal for smaller vessels, designed to run small hydraulic drives and mechanical drives for vessels up to 10 meters (33 feet) in length. Also provides solenoid output.