that I'm ever so glad I remedied, I was a supervisor at a nuclear power plant. My job required supervising people who work in high places on large equipment. Falls were always an issue and received lots of attention. My peeps were required to wear full body harnesses with a breakaway shock absorbing theaters of not more then 5 feet long when working in an elevated position. Even on a 5 foot step ladder. It was always a joke that you would hit the ground before the tether stopped you. You were suppose to fix your tether high enough that it didn't happen but people rarely did. My point is that even a short fall can develop so much force that with any harness, including a full body harness, you can be severely hurt. Couple that with a wave pushing you or the boat rolling you, and you don't stand much of a chance to survive injury free. With anything other then short tethers you're pretty much fooling yourself from a shock loading standpoint. Longer tethers might keep you hooked to the boat but you might be so beat up that you wouldn't survive after you were retrieved hurt, wet and cold. Size/length does matter.