calculation Because the hull speed is related to the length of the boat and the wavelength of the wave it produces as it moves through water, there is another formula that arrives at the same values for hull speed based on the waterline length. where is the length of the waterline in meters, is the hull speed of the vessel in meters per second, and is the acceleration due to gravity in meters per second squared. This equation is the same as the equation used to calculate the speed of surface water waves in deep water. It dramatically simplifies the units on the constant before the radical in the empirical equation, while giving a deeper understanding of the principles at play. Hull design implications Wave-making resistance depends on the proportions and shape of the hull: many modern displacement designs can exceed their hull speed even without planing. These include hulls with very fine ends, long hulls with relatively narrow beam and wave-piercing designs. Such hull forms are commonly used by canoes, competitive rowing boats, catamarans, fast ferries. For example, racing kayaks can exceed hull speed by more than 100% even though they do not plane. Heavy boats with hulls designed for planing generally cannot exceed hull speed without planing. Ultra light displacement boats are designed to plane and thereby circumvent the limitations of hull speed. Semi-displacement hulls are usually intermediate between these two extremes. See also Ship resistance and propulsion Wave making resistance References A simple explanation of hull speed as it relates to heavy and light displacement hulls Hull speed chart for use with rowed boats On the subject of high speed monohulls, Daniel Savitsky, Professor Emeritus, Davidson Laboratory, Stevens Institute of Technology Low Drag Racing Shells External links Converter: knots > km/h & km/h > knots Marine propulsion Fluid dynamics Water waves