Of course it takes almost 12hp per ton to get there.

does this mean that an 18 hp outboard will propell my sailboat at 32 kts?

The rough rule of thumb is that one HP for each 500-600 pounds of displacement is required
to push a boat to near "hull speed." If the required speed is reduced to S/L of 1.05
from 1.34, one HP is needed for each 1000 pounds.


"Wwj2110" wrote in message
...
Of course it takes almost 12hp per ton to get there.

does this mean that an 18 hp outboard will propell my sailboat at 32 kts?

The URL below points to an article about Annapolis resident Clay Oliver,
inventer of the hula skirt and designer of the mega-yacht, Mari Cha
IV, which just set an Atlantic crossing record breaking the previous
mark by 2 days. It also set the 24 hour record which was set in the
Volvo race.

http://www.hometownannapolis.com/cgi...3/10_16-18/SAL

Unfortunately the picture that was in the ODT edition is not on the web
page and I couldn't find one of MC IV on the net.

Joe Wood

Steven Shelikoff wrote:

On Wed, 15 Oct 2003 23:17:29 -0400, Joe Wood
wrote:



Jere Lull wrote:

Jim Woodward wrote:



Your dinghy may not do it, but it is possible to fool the water -- the
Kiwis tried it in the last America's Cup


As I recall, that attempt didn't work particularly well....

But our little boat with a wide flattish transom considers hull speed
(1.34 x sqrt(LWL)) a suggestion rather than the law. It seems the AC
boats and other newer sleds are more advanced that way.


Two points he

1. Hull speed only relates to displacement hulls. Planing hulls such as
the aforementioned sleds are another story.


It also only applies to displacement hulls with a L/W of less than
around 3 or 4. When you get to the 8-10 range, you can easily exceed
hull speed, as catamarans (also displacement hulls) do.

Steve

http://www.mari-cha4.com/

She averaged 19.5 knots over the 6+ days of her TranAtlantic crossing but
her theoretical hull speed is about 16. Her top 24 hour pace for 525 miles
was 21.9 knots.

I bet they were smiling.

Matt/Meribeth Pedersen wrote:

http://www.mari-cha4.com/

She averaged 19.5 knots over the 6+ days of her TranAtlantic crossing but
her theoretical hull speed is about 16. Her top 24 hour pace for 525 miles
was 21.9 knots.

I bet they were smiling.




With a hull that long and skinny, I doubt she's limited to 1.34*sqrt(LWL)

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/