I have had other chain stoppers, but I like this one the most. It came with the boat so I don't know if it is homemade or commercial. It would be simple to make and is foolproof to use.

It is a piece of heavy duty square aluminum tubing with a hole for a keeper pin. The pin goes through the hole in the shank of the anchor and secures it to the deck.

The pin looks to be the type used on tractors (I bought a spare at Tractor Supply), does not rust, and can be clipped to the rail when not in use.

Wish I could take credit for this idea, but it came with the boat. *