Chip:

I was one of those in earlier discussions who made the very strong point that it is very difficult to tell if folks have flown near clouds and you certainly can't do it from an igc file. Cloudbase is not known with any precision and can vary thousands of feet over a typical contest task area. I have on at least one occasion flown over cumulus clouds without violating any FARs and know of several occasions where other pilots have done so. Comparing flight traces of pilots with each other or a reasonable guess of cloudbase isn't going to tell you very much.

An entirely different question is the practice of staying in thermals until you reach cloudbase and then exiting through the wispies. It's hard to judge when to leave a strong thermal and this can happen to the best of us. I see it a lot of this in both pleasure flights and contests. I don't know how you would make an enforceable rule to control this, unless you are going to add cockpit cameras and dew-point sensors (quite doable, by the way!)..

Mike