Hi
i am new to model making and would value any advise given , i am about to build a submarine from scratch, it has to be a static diving sub be able to maneuver on and below the surface, the hull will be made from 5" plastic tube, driven by a torpedo 850 motor, i am going to use a compressed air ballast tank for diving and surfacing, i realise that this is a difficult challenge and would be grateful for any advise.