It an Aeroplane that can be a boat, a plane or even a submarine. currently, it cannot take off or land, that's why I didn't bother adding landing gear. VTOL up to start the main props then press AG 1 to make them faster. AG 2 starts the old props (i don't know why I left them there but they look cool. it is based on the old twin prop and Thorondil's "going the distance" plane. To get it to go underwater you need to start on water landing then VTOL up and press AG 1 and then pitch down and there you have it you can control a plane underwater (or you could just have it flying around and fly into the water).

It is also rather hard to start flying it from mid-air and so I recommend to start on water takeoff then VTOL up and press AG 1 immediately.