That last one is 22' long, and specifically designed to go at a speed of 10-20km/h. At those speeds it's smooth and non pounding. As soon as more power is applied, it climbs up on its flat rear sections, sticks its bow in the air and gets up to 40km/h.
The first one is my little D5 dinghy. It is very smooth and easy to move at low speeds as the curved stern provides little drag, but apply more throttle and it just digs a hole and burns fuel.
The middle one is the one I'm building now. Hopefully it will plane!