• 28 July - added 49er RYA "Recorded Number" PY.
• 8 January - changed 49er hull, crew and all up weight as per Jim Champ.
• 7 January - added 49er, Int'l Moth, UK Cherub and Avenger values from Jim Champ.
• 7 January - changed FD and E scow to retain jib/genoa area downwind.
• 6 January - change ratios to square root of sail area divided by cubed root of displacement volume.. as per Paul Kamen.
• 6 January - changed upwind and downwind sail areas to reflect normal upwind and normal downwind (some boats douse jibs/genoas when they hoist kites.
• 31 December - update main, jib and spinnaker areas for some boats... thanks to Marcus Ward and A Field Guide to Sailboats.
• 26 December - alter I14 spinnaker area and weight as per Pete Mohler, US I-14 measurer.
• 26 December - change ratios to square root of sail area divided by cube root of displacement as per Paul Kamen's suggestion. As I understand Paul's point, having both units in a linear (rather than a squared or cubed unit) makes the ratio a better comparision between boats of rather different sizes and weights..

First some notes:

• Upwind ratio is the square root of upwind sail area (in square feet), divided by the cubed root of the total displacement volume (which is in cubic feet).
• Offwind ratio is the square root of TOTAL sail area (main, jib when appropriate and spinnaker in square feet), divided by the cubed root of the total displacement volume (in cubic feet).
• I am assuming that the Thistle, Lightning, J30, J22 furl or douse their jibs when the kite is up.
• I was not able to find complete information for the Flying Dutchman (all up sailing weight), Star (optimum/typical crew weight, and all up sailing weight). For the E-scow, the sail area on the Johnson and Melges web sites differ (the Melges E-scow specs quote higher numbers), I used the Johnson numbers as per Dierk's e-mail. The (current rule) I-14 sail area values are approximate.
• USSA Portsmouth handicaps are from the current (1997) USSA Portsmouth Yardstick manual (not available on the web, USSA wants you to buy the D&$#* book for $16 plus shipping).
• Where I could find a range of crew weights on a class web page, I used the center of the range. Some of these values were altered after I spoke with experienced sailors from that class... For the J22 and J30, I used the maximum crew weight allowed by the class rules, as I believe most of these classes tend to race at very near the maximum crew weight.
• I assume the USSA Portsmouth International 14 rating does not yet represent the 1st generation 14s built after the rule changes of last year.
• Johnson 18 USSA Portsmouth numbers are incomplete due to lack of data points, the 85.7 is provisional.
• UK Portsmouth numbers are from Ken Turner's Sailing web page at URL: http://www.cs.stir.ac.uk/~kjt/sailing/portsmouth.html
• I-14, Johnson 18, Melges 24, Lightning, J30, J22, Thistle, Star, and E-scow RYA Portsmouth handicaps were not listed. I do not know if RYA Portsmouth includes ratings for some keelboat classes. Perhaps the I14 rating has not been determined since the I-14 rule changes. To the best of my knowledge, the Johnson 18, Lightning, Thistle, Star and E-scow are not commonly raced in the UK.
• USSA Portsmouth ratings are essentially saying that the 505, rated at 80.2, would sail in 80.2 minutes the same distance around a typical race course as a 470, rated 86.6, would sail in 86.6 minutes. Lower numbers indicate faster boats. Lower numbers also indicate faster boats under the RYA handicap scheme.
• I used the overall USSA handicap number, rather than provide the four different wind range numbers for each boat.
• Several e-mails to me pointed out that boat weight was worse than crew weight. I quite agree - weight you can move around is much better than weight you cannot. None-the-less, it is still weight you are dragging around the race course, so the "system weight" remains as the total of crew weight and the boat's all up sailing weight. All up sailing weight is what the complete boat (everything less sails) weighs (most classes define it by excluding sails, I simply used those number rather than estimate what sails weigh for each class).
• These figures do not include the righting moment. A trapeze boat can generate more righting moment from the same crew weight than a non trapezing boat; a double trapeze boat more than a single trapeze boat.