I am setting up my Skerry rudder. The rudder deployment line pulls the rudder into place for sailing. I get that part.
What about when I’m not sailing, pulling the boat out of the water or putting it in? The rudder is just loose, not held in place by anything, which would seem to complicate these operations. Any advice on how to handle this?
Yeah, that’s kind of left to the user’s ingenuity. For me, I have a long enough line on the downhaul that I loop it around the raised blade a couple times w/ a half hitch and that holds it up. To raise it, I uncleat the downhaul and either the shore bumps it up or I just reach over the stern w my hand and lift it. I do have a pretty long reach though. 
I guess you could drill the back edge and use a small diameter bungee cord or a second string but I haven’t done that. You can see the line coiled up in the pic below, dangling from the jam cleat w/ fairlead that I used on the top of the rudder arm, but uncoil it and it wraps around the blade, bring it up and put a half hitch on itself at the top.
You could also steal an idea from the Peapod or other boats and use a star knob to tighten the rudder blade in place. If you get the friction right, the blade stays down while sailing but gets bumped up and stays up when it hits bottom. Don’t know if it would work better than Mummichog’s idea but it’s cheap and worth a try.
Laszlo
Laszlo, I actually got one of the star knobs in my skerry kit, but I didn’t like the extra bulk sticking off the side of the rudder. My old racing sailing aversion to drag kicked in and it just looked….draggy. So, I drilled the blade and rudder cheeks a bit larger for a piece of stainless tubing with ID just big enough for the blade’s pivot bolt (1/4” I think) as a compression tube, and larger OD stainless washers and a nylon insert locknut. By filing down the length of the tube to just slightly less than the stackup dimension of the cheeks plus blade, it sets the compression on the blade and prevents overtightening the cheeks/blade, but lets you put some torque on the nut. Works for me, but of course means I can’t hand tighten on the blade on the fly.
BTW, I once yanked the downhaul a bit too vigorously and the knot in the blade split the plywood around the hole that you put in the edge of the blade. So, I repaired it w/ epoxy, used filled epoxy in the hole, redrilled in the epoxy, sanded and resealed everything and I hope it is now more resistant to that kind of failure.
