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post #23 of Old 07-22-2017
Jeff_H
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Re: LOA vs LWL, looking for a boat

Quote:
Originally Posted by jackdaw View Post
It's way to easy to overthink LOA vs LWL. Pick the boat you like regardless.

Many think that max LWL for a given LOA is best and it often is good, but not always.

My little boat (the First 260) is plumb on both ends, and has a delta between the two measurements of FOUR INCHES. Fun right? Max hull speed right? Mostly, but in lighter airs BELOW hull speed, its just more paint to drag through the water. High LOA/LWL ratio boats are often sticky in light airs. Hull speed only matters when you can get to it.
Quote:
Originally Posted by albrazzi View Post
Interesting, I never thought of it that way.
There is a good reason that you never thought of it that way. There is no reason to think that a boat that has a long waterline relative to it's length on deck would be "sticky" in light air. A particular design might be sticky in light air but not because it has short overhangs.

In the case of the First 260 it has an SA/D of 19.9, and it takes an SA/D in the mid 20's to get decent Light air performance. It also dragging two rudders through the water, one always slightly cocked so as to create drag but little steering.

Light air performance is all about sail area to wetted surface, and to a lesser extent sail area to displacement.

Wetted surface is all about the shape of the boat in the water, and it doesn't care whether there are long or short overhangs in flat water. In a chop, a boat with long overhangs tends to pitch more, and so if equally shaped below the waterline the boat with short overhangs should be less sticky.

Jeff


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Last edited by Jeff_H; 07-22-2017 at 07:41 PM.
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