One last item in the comparison above. This was a steeplechase format racing around permanent marks located in Choctawhatchee Bay in 10-15 knots of wind. The spinnaker boats probably got to use their chutes for 25% - 30% of the rhumbline distance of the race. It would be interesting to see how close it would have been if the actual utilization of the chutes would have been closer to 50%. This at least leads me to believe that the modifiers for spinnakers in the Portsmouth ratings are in the ballpark.

Fun stuff.