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November 16th 2019 - 21:25
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Hull speed

The theoretical speed that a Boat can travel without planing This speed is 1.34 times the square root of the length of a Boat at its waterline. It is based on the physics of how water is displaced by the vessel:

As speed increases a wave is created near the Bow where water is pushed away (displaced) by the vessel to make room for the Hull, another wave is created near the Stern, as water returns to fill the hole left by the Hull. Physics tells us that as the speed increases, so therefore must the wavelength. as the two peaks separate - as some speed the Stern wave will move behind the Stern and the vessel will begin to sink into itīs own trough - this will raise the bows. It is at this point that a plaining-hull will raise up and atop the water (escaping itīs Bow wave). Displacement vessels, are forever trapped behind their own Bow wave - so the faster they go - the more water they are forced to push, and thus the more power it takes - the Hull speed is that point of equilibrium where an increase in power will cease to have any significant effect on speed as a result of this.



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