: I once saw an anchor for small boats like kayaks that had a clip with teeth
: and a rope attached, to clamp onto weeds like cattails, etc.

: John

For the last 12 years I have just used a 6-inch plastic spring clamp from Harbor Freight with a hole drilled in the handle and a poly-pro (floating) line attached on one end and a small brass spring clip on the boat end. Works great! I can't imagine why anything else would work any better.