None of the sloops with main only could keep up with the Unis, even before the carbon mast (CRAM experience). The carbon has proven to be faster than the aluminum for everyone in CRAM. Now it looks like the 99 and newer vinylester boats are faster than the older ones. Most of this is not reflected in portsmouth numbers. You might have grounds for negotiating an appropriate portsmouth number with the race organizer. It probably won't help much at a major regatta, but the smaller regattas may be open to the discussion based on experience in CRAM which regularly gets 10 NACRA 5.5 Unis to the start line for most of its regattas. If I were sailing a NACRA 5.5 Sloop with only the mainsail, I would be talking about a more reasonable number with the regatta organizer. The 5.5 Uni number was lowered primarliy based on the CRAM data and the winning Unis in CRAM are all vinylester boats with carbon masts.

BTW, Uni mast is more than 30' tall. I thought the sloop was less than 29' tall, more than a foot difference.