My Tophat came with an Autohelm ST2000, which is currently working with no problems. As I usually sail solo, the self-steering system is quite critical. If I can set off for some multi-day cruises, possibly with overnight sailing, I would be in fear of the autohelm failing. I am quite taken by the idea of a vane system, with no power consumption, but this may be over-capitalising the little Tophat. A cheaper alternative would be to carry a spare autohelm (even an ST1000). I probably have just enough house battery and solar to run constantly, but would need to closely monitor same.

The ST2000 is purely working off the fluxgate, with no reference to wind, so needs to be re-set for direction changes.

I have had reasonable success with a lashed-helm system when close-hauled (using small link stainless chain onto the autohelm pin); but when the wind is on the beam or abaft, the Tophat needs much closer attention, especially if the following sea is over 1 m.

So, brains trust: is it worth carrying a spare autohelm? Do any of you solo sailors carry a plan B?