I use about 6' of strap and tie it off so the drift sock is perpendicular to the kayak. I don't use the anchor trolly because the perpendicular configuration slows the kayak the best. I use a clam cleat to tie off in case I want a quick release (I use this same quick release system for the anchor when using the trolly).
A drift sock is used to slow down the drift caused by strong winds. This will slow your drift so that you may cover an area longer or to slow you down enough to drift fish. Different sizes will slow you down based on the area of the sock. Most recommend about 18" to 24" drift sock for a kayak, depending on the windy conditions and how much you want to slow down. You can also use an anchor chain for slowing down your dirft. Just be sure to use one of these in sandy bottom conditons where there are not a lot of snags. Most anchor chains are used in rivers with shallow bottoms.
To use a drift sock, open it, tie it off and release it in the water on the upwind side. The wind will push your boat until the sock engages. I have a small float on mine so in the event of a quick release to fight a fish or something doesn't feel right, I can recover it later. Too long rope will cause potential snags of your fishing line as you fight a fish.
Never use a drift sock in current. A strong current could pull your boat under.Edited by gnelson651 - 12/19/11 at 11:54am