We've seen some vane installations that looked hopeless from this point of view, yet their owners managed to use the vanes successfully. I think that there a several factors to consider:
First, absolutely clean air flow is not present on any boat going to windward, so while adding new stuff in the way could degrade the flow further, it isn't a all or nothing situation. Further, many boats will steer themselves to windward without the input from a vane. This relieves the vane from steering
very much on that point of sail, and the effects of turbulent flow may well not be a big deal.
As you fall off from close hauled, the influence of an arch, etc, diminishes. By the time you are on a beam reach, the air flow to the vane is not badly disturbed, and downwind it matters not at all.
Further, it is possible to mount the vane itself remotely from the steering gear
on some models of windvane steering, eg the Autohelm
. This could eliminate the issue completely.
In practice, I don't think an arch with solar panels
mounted horizontally on its top would in itself be a big disturbance to air flow. Add a dinghy
in davits right in front of the vane... well, that is a worse situation for sure. But, IMO one should not have a dinghy in davits offshore anyhow, so some rethinking here might be in order.
Anyhow, I too endorse wind steering for any cruising yacht. I built one for our previous boat and it steered us many thousands of miles. Would like to have one on Insatiable II... I really miss having one.