CDC,
You'll hate the cost but, I got both of them at West Marine in Anchorage. They come with a phony little chain to attach to the boat but as you've no doubt noticed, I haven't had much luck with that built in safety device. This last time (I hope) I spliced a length of cord to the hook and attached that to a piece of wood too long to make it through the hawse (sp) pipe and so far have hung on to it. It was a quickie set up and will someday attach it in some way to the inside of the boat, but it does for now.
Bill