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To: PHRF Handicappers
From: Rod Johnstone, Designer

Subject: Recommended PHRF Ratings for J/Boats in 2008

The relative speed of various models of J/Boats in seconds per nautical mile is listed below. The table shows relative predicted speed of each model compared to one of five “control” J Boats, each in a different speed range, whose actual performance has become widely known in many PHRF areas over many years. The five “control” J Boats used in this comparison are the J/44, J/35, J/29 (Masthead outboard), J/30 and J/24. Assumptions are that:

1. Except where noted as “One Design”, each model conforms to all local PHRF definitions of an unmodified “base boat” with a base 150 to155% genoa (depending on local regulations).

2. Maximum spinnaker size (without penalty) conforms to local PHRF regulations defining base spinnaker size, except where One Design definition of spinnaker size accompanies the speed prediction shown in the table below.

3. Wind strength averaging ten knots is used to predict relative speed. Because most J Boats have similar characteristics in different wind strengths, this is a valid way to predict speed differences versus one of the five “control” boats over a wide wind range.

4. The race course length is 40% to windward, 40% downwind and 20% spinnaker and jib reaching. Most PHRF racing occurs on windward-leeward courses, but a reaching component is necessary to account for some point-to-point racing and for triangular courses. If courses used for racing are strictly windward-leeward, then base PHRF handicap numbers suggested for J/Boats using asymmetric spinnakers tacked to centerline sprits (or to the bow of the boat) should be increased by 3 sec/mile.

5. Crew Weight: Our rating recommendations for PHRF numbers for J Boat models designated as One Designs does not include one-design crew weight limits. It is assumed that PHRF crew weight limits, if any, shall apply equally to all types of boats racing in a given PHRF area, and that the One design designation only applies to the boat, rig and sails. Therefore One Design Class Rules regarding crew weight should not apply when using these PHRF rating recommendations.

PHRF ratings of the five “control” J/Boats may vary somewhat from one PHRF area to another. The PHRF numbers shown are what seem to be typical for these five boats nationally. If the PHRF number shown here is different for the applicable “control” boat in your area, apply the difference to the relative rating of the J/Boat you are handicapping. For instance, if the J/35 rates 66 in your area rather than 72, as shown on the attached table, the number for the J/Boat you are rating would be six s/m less than what is shown.

Please direct questions, input, or comment on these suggested relative J Boat ratings to me at rodj@jboats.com, or tel. 860-535-3480 or fax 860-535-3481.

Rod Johnstone

PHRF Handicaps for J/Boats

Assumes average wind speed of 8 to 12 knots. Maximum genoa and spinnaker size conforms with PHRF norms, except where shown below. Course is 40% to windward, 40% running, 20% reaching.  Crew weight maximums are according to local PHRF regulations. Sprits are all non-articulating.  Suggested ratings for one design boat configurations below assume full crew as allowed by local PHRF regulations for all boats (as opposed to one-design class rule limits).