: Does anyone have an idea on a good size hole to use to get as water tight a
: seal as possible with 3/16" shock cord?

: Joe, I used that system, but right offhand I don't recall the hole diameter. What I did was to drill holes in a scrap piece of deck until I found the smallest hole that I could get the bungee cord through. That is probably the best method, because drill bits of the same size don't always drill the same size hole. (wobble in the drill chuck, off center grinding of the drill bit, etc.)Cut the bungee and work some of the outer covering to a point. stick that through the hole and pull hard. A pair of smooth jawed pliers helps to pull it through. Work as fast as you can because the rubber cords in the bungee trys to spread out fast. You can put some Marine Goop on the knots, but if you have a tight enough hole, there willl not be much leakage. I don't have it Goop on mine and I haven't noticed any leaks.

Ronnie