You may have seen a TillerHand on the tiller of little Grace.
TillerHand in my humble opinion is good for giving some resistance to tiller movement so you can let go for a few moments but it is not easy (fiddly) to lock it off completely and by the time you have it needs adjusting. Perhaps more useful and the fiddling not a problem when you don’t have to make a lot of adjustments in open water but where I sailed last year I found I was yearning for something I could release and know the tiller was locked but that would free up when I took hold of the tiller again.
I was half way to designing one on the back of an envelope when I came across TillerClutch. I have not been able to try it yet because of the problems with the hull of Little Grace but it seems to be everything I was hoping for.
Update: The line used by the Tiller Clutch gets in the way when starting the engine and manovering at slow speeds. Otherwise it is a great improvement that makes it possible to leave the cockpit for a few moments, to deal with sails, lines, fenders, check the GPS etc. or even go into the cabin to check the chart.
Just as important, on returning to the helm, the tiller clutch is released with one movement of the leaver and course corrections can be achieved quickly.
Click here for some video for the Tiller Clutch in action on Little Grace.