SEOUL — The South Korean Navy has a submersible that also doubles as a surface vessel.br br According to Korean Naval manufacturer VOGO, the vessel can be deployed via airdrop from a C-17 or C-130 aircraft. It can carry a crew of 10. br br On the surface the SDV 1000W can travel at 35 knots, or 40 mph via diesel engines and waterjet propulsors. While submerged it can travel at 6 knots or 7 mph using lithium polymer batteries and silent electric motors.br br Submarine expert H I Sutton reports that the vessel functions like a wet-sub, in that the crew still wear diving gear and receive oxygen from a sizeable on-board air system. This lets passengers exit underwater, but the vessel can also be run up a beach.