Displacement hulls were first used at the turn of the century, when internal combustion engines were large and heavy. Morley S. Smith - lesliefield.com. When a displacement hull moves through the water, it pushes the water out to the sides. Most displacement hulls are long with a narrow bow. These hulls are the easiest to maneuver at low speeds. Semi-displacement hulls are slightly flatter. Semi-displacement hulls are identified by three factors: 1. The shape of the ride. 2. The relationship between length and displacement. 3. The amount of “V” or draft of the hull and generally have a hard chine or well-rounded bilge. - Pelly Marine. Semi-displacement hulls are versatile and combine speed and seakeeping. Planing hulls have a rigid structure and a sharp edge between the hull side panel and the side panel. Morley S. Smith – lasliefield.com. When planing hulls are in motion they push the bow down instead of pushing water to the sides like displacement hulls. It turns out that if you have a flat bottomed boat the aerodynamic drag will be less. The less drag the boat has, the smoother the ride will be and the smaller the boat's angle of attack will be. Most planing hulls today are made with a V-bottom. Height and weight have a large effect on speed. Planing hulls tend to skim the water more rather than move through the water. The stepped hull concept was proposed by Rev. Ramus of Sussex, England in 1872. He proposed both a single slip with tandem planing surfaces, and a combination of three pontoons including one in the bow and two in the stern. Morley S. Smith – lasliefield.com. After discovering that steam power was not powerful enough to move the hull fast enough, William Henry Fauber moved to Europe with this idea in... middle of paper... trying to make it possible in the near future. future. Since the idea of ​​a Surf-Step hull is a relatively new idea, there are still many other modifications and specifications that need to be made. Some modifications that should be made are an extension of the bottom aft on both sides of the propeller to reduce hull drag. A further improvement would be to place a cover around the upper section of the propeller. A lip on the cover aft of the propeller would help pressurize the water onto the propeller. If this extends to the side extensions of the hull, the propeller will operate in a tunnel formation. The main hull step should be positioned forward of the center of pressure to avoid porpoising. The forces produced by the propeller piercing the surface, move the center of pressure well forward of the center of gravity.Engines/Engines