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Old 01-31-2013
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Re: D/L Ratio Questions for Cruising Boat

Cold,

I didn't re-run the numbers so I will assume you did the math right. Given this there are a few things to consider. D/L is not really so meaningful a number. Unless you are comparing two very very similar boats the numbers can be very misleading.

1) a boat that uses a lot of carbon fiber will have a much lower D/L than one that uses CSM. Simply because one is much heavier. But when you look at performance they will be almost exacally the same.

2) a boat with deeper draft can have a lower D/L than one with a shoal keel because less weight is needed to generate a given amount of righting moment.

3) a D/L of 150 is not really that low. Say in the light cruiser/racer catagory.

4) a boat with long overhangs will have a lower D/L even if everything else is the same. Since D/L uses LWL not sailing water line.

Finally while I know and respect the oyster, I don't have any familiarity with the …lan. But my thought is that Oyster must have been pretty impressed by the designer if they offered him a design job.
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