the flat bottom i think
You may mean a planing hull. That is a shape of boat hull that "planes" or rides on the top of the water at high speed, rather than plowing its way through the water.
A displacement hull always displaces an amount of water equal to the weight of the boat. A planing hull at a certain speed, will begin PLANING and rise partly out of the water, forced up by its v shaped hull, and only be displacing an amount of water equal to partial weight of the boat. A large ship, a tugboat, a barge, or a sailboat are displacement hulls. A speedboat or a jetski are planing hulls.
No, a ragged-bottom hull typically refers to a hull shape that has uneven or irregular surfaces, which can affect the boat's performance in the water. Planing hulls, on the other hand, are designed to lift out of the water at higher speeds, reducing drag and increasing efficiency.
The plural form of "hull" is "hulls."
A planing hull has which of the following characteristics
Planning hull
flat bottom hull
Deep V hull Depending on how rough, I've found that a 'twin hull' type of vessel handles chop and moderate swells very well. The 'cushioning' effect caused by the air trapped between the two hulls takes a lot of the bang and shudder out of travelling in rough weather.
Displacement and planing
A trimaran has 3 hulls, a main hull and two smaller outrigger hulls.
a displacement hull is like a canoe's hull... it displaces water