I don't trust GPS max speeds. My GPS has clocked me doing 35mph and it's just not true. I'm not sure why perhaps because it swings around when I have it on me.
I do trust the constant readout of the GPS of course I think it is very accurate. Here are two runs that I've made below.
1. Hobie 20 Double trapped reaching in about 18 mph winds. My GPS consistently read 23mph.
2. 2003 Steeplechase. Double trapped chute run on the second day. I had the courage to look at my GPS a couple of times. We were reading a consistent 25mph. However if you look at the point to point times they won't read that fast. The Steeplechase has to wind through some cuts in the mangroves and some shallows which really slows teams down.
If you can find the times for the Worrell in 2001 for the first two legs you probably will get a decent top speed for a cat in open conditions without a chute. Perhaps someone that has done the Worrell or Tybee can chime in with a day that they thought was particularly fast.
Mike Hill
www.stlouiscats.com