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Old 08-30-2009
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The cruising speed you speak of (1.34 x the square root of the waterline length) is the theoretical hull speed (maximum speed before trying to climb its bow wave) of a displacement hull, its ideal cruising
speed for economy would be slower, probably bout 80% of that speed. You have a planing hull. It isn't as efficient following the same rule. Quite often a planing hull at the speeds mentioned, in other words displacement speeds, will be trying to climb its own bow wave and appear to be trying to pull half the ocean behind it. Not very efficient. What design is it? Your best bet is to contact the designer and find out from him what the given hull is designed to do. There are planing hulls and displacement hulls and everything in between, seemingly small changes making a fair difference. Without knowing what the hull design was optimized for it's hard to determine the optimal speed.
Brian
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