The "S" Number

In the February/March 2011 issue of Professional Boatbuilder magazine, the ROVINGS section by Dan Spurr, there was a summary of a section of The Design Ratios by Eric w. Sponberg of SPONBERG Yacht Design Inc. dealing with the S Number. The S Number is a formula that assesses relative performance of sailing yachts, giving values that range from 1 to 10
The Multihull Dynamics, Inc. website has used the term Base SpeedTM to do comparisons of performance potential. It results in a projected Best Days Run speed over a 24 hour period under racing conditions.

The article roused Cal Markwood’s curiosity, Engineering Analyst for Multihull Dynamics, Inc. He was interested in the applicability of the S# to catamaran sailboats and how it compared with Base SpeedTM as a method of evaluating performance potential.

The S Number http://www.multihulldynamics.com/news_article.asp?articleID=232

Pat Ross

 

This is a multiple post

 

S number

Warranted in this case because it applies to monohull and multihull sailboats. Thanks, Pat!

 

There was a link problem, it is now repaired.

http://www.multihulldynamics.com/news_article.asp?articleID=232

Pat