Jul 17, 2007

Phillipe asked and Phillipe gets

He asked me the same silly question. The longer the boat, the faster? I read this about two years ago. I agree with Matt.

Here is an answer by Matt, a maverick boat designer.

"Longer boats are commonly regarded as being 'faster' than shorter ones. The reality is, as usual, more complicated. I would rather say that longer boats have a higher potential speed; you still need to supply the energy to achieve that speed. If you don't feel like working that hard ( and it can be real hard in a headwind and sea) then you will go slowly, and the guy in the shorter boat will keep up with you just fine at the same power output. Sorry, here comes a little math: A boat's speed (in knots) can be expressed as a factor of the square root of its waterline length (in feet), V / sqrtL, the Speed-Length Ratio (or Taylor Coefficient). With variations from other factors, generally a boat is most efficient (best speed from least effort) at S/L ratios around 1.0. The maximum speed a boat will usually reach under sail or paddle ('hull speed') is close to a S/L of 1.34."

Well, that is only 1/4 of the full text. Click here for more. Search for "Some Design Factoids"

1 comment:

Stevie said...

Another thing to think about, shorter boats are more effected by waves than longer boats. This can be good if you are surfing, but bad if you are trying to get somewhere head on into waves.