A submarine is comprised of a hull with an external seat on top and a backrest behind the seat. A control column and a grab handle are positioned in front of the seat. External drive motors attached to the hull drive propellers housed in protective cages. Servo driven dive planes and stern rudders provide directional control. Batteries are attached to a mounting plate positioned in channels inside the hull. The control column, drive motors, dive planes, rudders, and batteries are connected to a controller. A detachable safety key tethered to the rider is arranged to disable the drive motors and control column if the rider falls off and pulls the key from the hull. A water sensor on top of the backrest is arranged to prevent the diving planes from pitching down when the sensor detects water for limiting diving depth.