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Re: Odd Question
By:Jim
Date: 5/13/1999, 12:53 pm
In Response To: Re: Odd Question (David Bryson)

Doe this formula work for multihulls, like a trimaran?

> The theoretical speed (in knots)of any displacement hull type of boat is
> about 1.4 * (LWL)^.5 or said in english: 1.4 times the square root of the
> water line length. So, if the CLC 17 has a 15 ft waterline (i'm guessing)
> take the square root which equals 3.8 knots (nautical miles per hour)
> Multiple that by 1.4 adn you get 5.4 knots. This is as fast as you will
> ever go - unless you can surf down a wave. It is just impossible for the
> hull to push through the water any faster no matter how much energy you
> apply.

> This is why longer boats are faster boats up until you can no longer apply
> the necessary energy. An aircraft carrier is one of the fastest
> displacement boats in world for this reason. 1.4*(900ft)^.5 = over 40
> knots.

> However, you will never maintain this type of speed in reality. You could
> maintain 1.0*(LWL)^.5 or about 3.8 knots for a reasonably short period of
> time.

> But my guess is that you would be lucky to keep up 0.8*(LWL)^.5 or three
> knots for several hours. Waves, wind, tracking, all bring this number down
> further.

Messages In This Thread

Odd Question
K. Morton -- 5/12/1999, 6:12 pm
Re: tangental answers
lee -- 5/14/1999, 3:06 pm
Re: Odd Answer
Mike Scarborough -- 5/13/1999, 8:24 am
Re: Odd Question
David Bryson -- 5/12/1999, 9:55 pm
Re: Hull Speed
Nick Schade - Guillemot Kayaks -- 5/14/1999, 9:15 am
Re: Hull Speed
David Bryson -- 5/14/1999, 7:17 pm
Re: Odd Question
Jim -- 5/13/1999, 12:53 pm
Narrow hulls
Brian T. Cunningham -- 5/13/1999, 1:20 pm
Re: Odd Question
Robert Woodard -- 5/12/1999, 6:59 pm
Re: Odd Question
J . P. Scheib -- 5/14/1999, 3:39 am