Hey Thanks klaus, are you a professor at Hamburg? If not, you'd make a darn good one IMHO!

The asymmetric profile of the glider never occurred to me... That sure makes my comparison a case of apples and oranges...

And cats being "interface vehicles" (term I borrowed from Richard Woods) makes the hydrodynamics vs aerodynamics trade off a really big deal too.

I'll look into Reynolds theorem again although I have to admit I was never able to "get" it before. I just can't handle that much algebra.