"How do boats float?"
A magic called 'buoyancy'.
Try not to troll.
Also,
I believe it has to be a bot, not a vehicle, which sucks ass.
That's why it is a playertype, I think.
Because you can't be a "Tank Player", but You can be a "TankTurret Player".
which is due to the fact that the tank is a vehicle, and the turret is a bot mounted to it.