This speedboat floats upright with no change of infill and the hull is optimized for speed. This boat is also really stable when it is not moving or moving slowly because how how the hull is designed. This model does require support.

The model is really small so you can scale it up according to how big you want it to be.

Print:

This model's infill should be around 5% cubic but you can experiment with what fits your application. you should print this model vertically and support the cabin of the boat. The windows shouldn't need to be supported.