I can't really answer as to how far in you can go but this past June I touched down just behind the last row of balls. I was swinging around to starboard to head back up to a ball.
With the assistance of a friendly cat captain, I was able to pull back and out and then was careful to stay in the mooring field to get my call. My depth was reading 4.5 when we touched and I think the boat draws 5' 3" or something so it was "half-calibrated" or something.
I don't know if the tide was in or out as I never pay attention to it there. Next time I go, I'm going to just weave in and out of the ball/boats and not try to come down the outside. After this experience, I would not try to anchor downwind from the mooring field in a mono.
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