Tiny clam cleat or equivalent?

Thread starter #1
the rudder on the Sun Chaser II tends tilt up to the launch position under much wind. cranking down the nut helps, but then its hard to get up and down.

I have come up with a basic line-and-cleat idea to hold the rudder in place but easily let it go in shallow water. The missing part of the puzzle is a tiny cleat (1/8" line), since there is not much room to work with.

Any ideas for making a tiny clam cleat? I will probably fashion something out of wood to try out the concept, but a wooden cleat is probably not a long-term solution.

Thank you!