I'd like to add my voice to the chorus praising the very fine, very elegant, and beautifully executed fabrication. A first-class job indeed! Wow, I wish I could do that kind of work -- you are a true artist with metal.
Something tells me it is not going to be stable enough at sea. When the boat rolls around at sea, it seems to me, you're going to get some mighty strong lever moment on that stainless tube, and swinging, which will tend to rip it off -- to twist it out of its socket. The fact that the radar
scanner counterbalances the wind vane
will actually make things worse, when you get the whole contraption swinging around the axis of the stainless tube as the boat rolls -- the angular moment caused by the inertia of the radar
scanner will be added to that of the wind vane
But I'm not an engineer
and that's just a hunch. Do let us know how it works in practice; we're rooting for you!
Advantage of your scheme is that you've got the mass of your radar scanner out of your upper rigging
; also the whole mass of the structure is less than most anything else you could imagine. So if it just doesn't swing around too much, it will be a killer setup.