Don't go out into waves that you wouldn't feel comfortable swimming in. Same goes for depth... if you're not happy swimming in mast high waves out the back, then don't sail into them for goodness sake!!
The surf will smack your bum hard if you aren't confident in the conditions minus board+sail.
Speaking from my own experience

, I've got a lot more respect for the surf now... also be absolutely sure you can waterstart if the wind drops a bit!! Had to wrap the uphaul rope around my foot and swim back into shore last time I went out

Saw a guy last week who obviously wasn't confident sail into some decent surf, got to the outer breakers and snapped a universal joint. He didn't have his safety rope connected to both halves of the UJ, so his board surfed the wave in while he was left hanging onto his sail in 5foot whitewater, 100m out from the beach. What would you do in that situation?