US SAILING Launches SailRater, a Performance-Analysis Tool

April 29, 2002

What happens to my boat speed if I go from sailing upwind to reaching? How much faster will my boat go with a longer spinnaker pole or a larger main? Will my new keel make my boat faster or slower and by how much?

US SAILING’s launch of SailRater (, an online sailboat performance analysis tool will help answer these questions and many others for boat owners, without having to take the boat on the race course, make a sail purchase, or build a new rig.

SailRater calculates changes in predicted speed due to course changes, wind changes, or alterations to a boat’s configuration. SailRater also has an application to race handicapping and can help racers make boat-configuration decisions.


With a comprehensive “Help” section and tutorial, as well as step-by-step instructions, using SailRater is a breeze. After entering the boat’s PHRF certificate information and starting reference conditions, users tell SailRater the changes they’d like to make-for example, what difference would that larger main make?

SailRater makes VPP (Velocity Prediction Program) technology available to all monohull racers. The SailRater VPP is based on cutting edge data and uses the latest results from ongoing research in sailboat aerodynamics and hydrodynamics. The VPP uses this combination to find the boat speed at any wind speed and any heading relative to the wind direction. Hydrodynamics are derived from a large database of towing tank test analysis, aerodynamics from a database of wind tunnel tests and from practical experience.

The SailRater technology has been compared to VPP results using fully measured boats and performed comparably. PHRF associations have used the same technology to generate new ratings for races with different wind and course content.


To get started with SailRater, users must register at the secure location, accessible through Registered users can either proceed directly to the SailRater entry form or try several free example submissions for practice and to see how the system works. All data is stored on the SailRater secure server in the registered user’s private library, available for each visit to SailRater.

The cost is $15 per submission for using SailRater’s calculator to compute an answer to your question. Practicing is free. To register and get started on SailRater, visit

SailRater users choose between two different calculators, SailRater: Boat
and SailRater: Wind.


SailRater: Boat allows the user to:
–Compare different variations of the boat (or some version of it) on a single course with a single wind speed.
–Compare different variations of the boat (or some version of it) under varying course and wind speed conditions. (This will require running the calculator multiple times.)
–Compare the boat (or some version of it) to other boats boat on a single course with a single wind speed.
–Compare any base boat you enter in “My Data” area to any target boat from the “My Data” area.
–Compare base and target boats under varying course and wind speed conditions. (This will require running SailRater: Boat multiple times.)

SailRater: Wind allows the user to:
–Compare a single boat over two different courses, but the same wind speed.
–Compare a single boat over two different courses, but different wind speeds.
–Compare a single boat over the same course, but different wind speeds.
–Compare boat variations over different course mixes. (Requires running
SailRater:Wind multiple times.)

The concept of SailRater was developed at an Offshore Leadership Strategy retreat that then US SAILING president James Muldoon asked Bruce Eissner to organize and chair. Eissner led the section on offshore rule development and recruited US SAILING vice president Charley Cook to lead the discussions of offshore strategic planning. Leaders of IMS and PHRF from across the country attended. One of them was Dan Nowlan, from Southern California.


At the meeting, Jim Teeters, naval architect and US SAILING director of Research, presented his thoughts about a system for applying VPP know-how to single-number ratings in order to make those ratings more accurate in a variety of conditions. First called either The Handicapper’s Toolbox, or Ratings Plus, Teeters’ concept met many of the criteria that the group had identified for a successful rating system, including low barriers to entry, ease of application, perceived fairness and value, responsiveness to changes in fleets and boat design, and others.

Nowlan, Teeters, and Eissner continued to refine the product and the concept. After the meeting, when Nowlan became US SAILING’s Offshore Director and Eissner was appointed Chairman of the Offshore Committee, the three parties set a goal of making the concept, now named SailRater, easily available to individual offshore sailors as well as to handicappers.

Because the Internet was a natural medium for this, they enlisted the help of the Polar Cove Division of Orbidex, Inc. of Providence RI, where Seyha Phul, Director of Systems Development, and Erik Petersen, CTO, helped bring to life.

For more information about SailRater, contact Dan Nowlan, US SAILING Offshore Director at [email protected], or phone (401) 683-0800.

The United States Sailing Association (US SAILING) is the national governing body for the sport of sailing. The mission of this volunteer organization is to encourage participation and promote excellence in sailing and racing in the United States. More information about US SAILING, which is headquartered in Portsmouth, RI, is available at their website,


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