RE: What wave board?
Thanks again for your thoughts.
I realize the K96 is at the upper limit of size, but it's an entry-level move and I won't mind at all if it is more suited to the 6.5 range. If the board gets too big, I'll go to the Naish, which I think has a sweet spot in the 4.0-5.0 range. It handles pretty nice in big stuff as long as there is wind.
I'm thinking that if I like the K96, I'll probably complement it with a K79 or a similar Evo, as everyone has been suggesting.
FWIW, the viscosity thing was something I picked up in a listserv discussion about fins...maybe even here...and someone pointed out that the viscosity of water is highly temperature dependent. Very cold water is much more viscous, relatively moreso than the change in density. If so, then wind / water interaction would be markedly affected by temp, and so would the viscosity differences between fresh and salt water alter viscosity. Certainly, temperature has a big effect on air density and sail power at a given wind speed (a fact well known to sailboat sailors and airplane pilots). So I won't be surprised if someone shows that the wind/wave interaction is more affected by viscosity and density than is commonly appreciated.