BASIC ANCHOR ON A KAYAK

I have been following the post on the drift rig, however I was looking for something to hold us in place in the sound.  I know it can be dangerous to anchor in a kayak what should I be considering when I an looking at this?  I was thinking of putting a scotty anchor mount at the rear of the kayaks so that we could drop the hook and let our rigs drift infront of us or would the anchor trolly do this also and let us anchor on the side in still water? also do you find that the 6 or 8 pound anchors will hold a kayak in place?

Carl 

Either would probably work for situations in which the current isn't pushing hard.  5# will hold you no problem.

-Allen