I too can't stand sitting on the board for too long. It puts you out of paddling position and when you see a set coming in you have to turn and find the sweet spot on your board again. It's also uncomfortable. If nothing is coming in at all I'll hang on the board and float in the water, much more comfortable than being on the board. makes you look like a "kook" though
BCN - you got that right about being ready for the set on your board's sweet spot. Something I think of all the time out there.
I don't lay on my board like a corpse doing the dead man's float. If I'm prone, which is basically all the time, my back is arched with chest up to see the set coming in, ready to move quickly, and for all other times, just in an athletic posture. If that makes me look like a kook, then I don't ever want to look unkookish. This sit on your board all day crap is no different than sitting on an inflatable couch. There's far more stable objects for that at Wal-Mart if you're into that sort of thing.