Hey Richard,

I had a tiller extension that was adjustable. It was permanently
mounted atop the tiller just behind the hand "comfort zone" and when
not in use is lined aft and sits in a clip near the gudgeons. Similar
to:

http://www.pridemarine.com/index.cfm?category=10007|10169&product=4199048

If you were to find a way to clamp the "free end" of it to some point
roughly perpendicular to the tiller, like a gunwale or coaming. or
better yet to a cockpit seat, you would have what you want and a
useful gadget too. The "adjustable" part would allow clamping/holding
at any position you want within reason.

Take care.

Brian Lawson,
Bothwell, Ontario.