We talked about this last year allot of us had different ideas. Here are two of mine. Take standard dock lines 25' 1/2" with eye spliced in, tie large knots in the line at even distances. Take the spliced end and put it around a stanchion with a pass through the eye and if you fall over with a tether on and if you have done some measurements and placed the ropes where you would be hanging you have a SECOND CHANCE which is what we were calling the devices. a couple or more on each side where you do most of your deck work is a cheep insurance policy. Take them off when your coming into port ,tackie looking things like fenders hanging off the sides while your sailing.
Oh number two was a line draging behing the boat about one hundred feet if your scared you might catch it and pull like Samson.