Hebridean Wind vane Design
The secret of the wind vane's success (and sensitivity) is the horizontal axis about which the vane deflects. All other wind vanes deflect on an axis around 20 degrees from the horizon which is why they "feather".
Existing wind vanes "feather" into wind when they deflect. This limits vane deflection whatever the wind strength, but is necessary to damp the vane.
The Hebridean is different. The vane only "feathers" when the pendulum blade swings. Only then is the vane damped to stop over-steering. Until then vane deflection is not limited.
This "feed-back" mechanism of damping the vane from the swing of the pendulum to prevent over-steering is a unique feature of the Hebridean, and is why it is responsive in all situations and conditions. The simplicity of the design also lends itself to DIY construction.