What type of boat are you talking about and does it have or do you use Auto Pilot often? The reason I ask, is that I used to single hand our old Cal 25 all the time and I did not worry as much about a tether because if I fell, I was pretty sure that eventually the boat would stall out and round herself up. Doesn't mean my thinking was sound, it was just the way I felt. Unless the boat was perfectly balanced, it was going to stall. I would practice at balancing the helm all the time, and she would sail herself for a while, but eventually she would round up. Today, I am always using Auto pilot and I am much more concered about tether and harness. In any sort of winds when single, I am tethered. Smaller boat no auto, I did not worry as much. Call me crazy, I know.
Courtney is My Hero
If a man is to be obsessed by something, I suppose a boat is as good as anything, perhaps a bit better than most - E.B. White