Wow a 16 is my newest pick for the over 20. I think the Formula 18 has been taking quite a hit ratings-wise for the last couple of years with all the hot shots sailing them. I think the 16 rating will never change. I did not even know there was enough racing done by a Marstrom 20 to have rating...mmm.
Here is the weird part while you are on one of the "faster boats" against a Hobie 16 in more than 17 knots of breeze, Beauford 5 and up. Let's say you finishe the course in 30 minutes and you are on a Formula 18. Further, this course is three times around with a downwind finish. Seems short, huh, but it happens all the time. Now a Formula 18 is about 2 times faster downwind as upwind so each one of your weather legs are 7 minutes and downwinds about 3 1/2 minutes. You have also set or doused your chute 5 times. Then there is a Hobie 16 plunking along who gets an extra 6 minutes 20 seconds to finish this 30 minute race. Considering that the 16 is about the 1/3 faster downwind as they are upwind. We will call it 7.5 minutes up and 5 minutes down. For a course that is three laps they are not even at the weather mark when you finish. If this 30 minute race is 2 laps then they are just barely past the weather mark. This is one of the reasons that the courses are so short. In reality the good 16 sailors are sailing almost boat for boat, in these conditions, against the middle of the spinnaker fleet.
Three minute downwind legs, in a breeze, do not favor spinnaker boats in handicap racing.
Just some thoughts,
Dan