Re: Jackline system
What would be unsatisfactory about 1/2 inch nylon three strand run from port stern cleat through bow cleat to starbard stern cleat? Talking about a 28' boat. Can hook a double teather to port and starbord when in cockpit and unclip one and go forward with the other. The stretch would keep you from breaking your back when falling. Rolling under foot would be minimized as it would lie along the coach house, not in the middle of the side deck.
The only issue I see is unable to clip on before leaving the cabin.