Hi Clint,
Glad to see there is still off-the beach sailing in Durban - I`d heard the new development had closed PYC beach club and there was nowhere to launch anymore at Vetchies ?
Agree with your sentiment - if you`re going to be attached to the boat, good idea to be able to "quick release" - If you have a one-piece mainsheet and traveller rope you could try running it through a paragliding quick-release karabiner that is attached to the harness. If you fall overboard and are being dragged under or behind the boat at least you can hit the button, and it gives you enough time to grab mainsheet with both hands and hang on - you can then decide manually when the right moment is to let go (ie just before you pass out !)
Agree with Gary, there is sometimes no way you will swim back to a Hobie or any cat that is stable on it`s side being blown along at 4 knots, and in Durban I`d not want to swim back to the beach unless I`d capsized INSIDE the shark-nets, never mind 35 miles out(yikes Gary, what are you thinking ??? )