2003 PHRF book...
There are quite a few 28.5's in the PHRF book, broken into two groups...standard keel and shoal draft. The std keel rates from a low of 121 to a high of 201. Most are about 183-186. Lake Ontario has a boat at 171, and Detriot has one at 174.The shoal draft boats run form 180-195, most being 186-189. LAke Erie has one at 186, and Detriot has one at 183.What you really need to do is apply for a rating from your local PHRF board, and go in with LOTS of data to support your boat. It is a local decision based upon how your boat can performs in local conditions in 8 knots of wind. Comparisons to other boats by length, weight, sails, hull, keel, and many other conditions. The more info you have, the better your chance of an acccurate rating.Of course, if it is just for local club racing, then the club can give you a rating.Good luck,Steve