The top of the servo rudder should be above the resting water
line by 6" or more. Boats squat at the stern when underway so the self steering
rudder blade spends its life under water
even mounted properly. If yours is set up with the servo rudder head
out of the water at rest, then all should be fine. From the video, it seems to be working without any issues. Didn't notice excessive shaking or vibration.
Assume the video was taken under sail with the engine
not running. Depending on the boat, servo pendulum self steering
may not work well because of turbulence from the prop when under power. Our old Aries
with a non kick up servo rudder would shake like crazy if centered with the engine
on. Would swing the rudder all the way to one side to stop the vibration when powering. The prop on that boat was only a few feet from the rudder.
I have a WindPilot Pacific Plus that I bought second hand off a much larger boat. Mounted it as high as I could but the steering
was just below the water and the aluminum
rudder coupling was constantly getting dunked with even little wave action. It worked fine including a sail to Hawaii
but the coupling being constantly wet caused corrosion
problems with the cinch bolts. Took the vane to a machinist and had the support casting and rudder axle machined about 8" shorter so it now lives higher and drier. Still works fine. If it's possible to cut a few inches off the shaft to get the at rest height better, probably wouldn't be a problem. Might check with Peter before you do it though.