Center Cockpit Boats and Windvanes

[My Wind Lass]

Are there any wind vane systems or non electrical automatic helming systems that work well on a center cockpit sail boat? It appears to me that I have only ever seen a windvane used on aft cockpit boats. Is that because of any difficulty in connecting the windvane to the rudder system? I have a preference for buying a CC boat for the aft cabin option but I want to have a wind driven autohelm system for crossings and not be dependent on an electical system.

[Triumphant]

Hydrovane