I flew with a very excellent to-remain-unnamed pilot, who once flew 1000' above me when I thought I was at cloud base. Afterward, he said he wasn't in the cloud, because he could still see the ground directly below him. My rule for cloud base was/is that if I can't see the horizon, I'm in the cloud.

I agree that damn near every glider pilot breaks the cloud separation rules unless posting on a forum, simply because the lift is strongest there. I'm not saying it is right or wrong, but it certainly happens.

All that being said, what is the actual definition of cloud base, that we are supposed to stay 1000' from? I am not trying to be a smart-ass, I would really like to know.

And since I am high-jacking Richard's thread, I will add this: If you do put a stand-alone ADHRS in your glider, you will not be able to fly contests with it. As IGC regs require an ADHR activation to be logged in the file. Again, no judgment here, just passing along information.