rhys wrote in
:


Agreed, and I know what you are getting at. But if seas are flat, wind
is calm, and you are on a misty seaway at dusk/dawn motoring at five
knots under autopilot, I can see where a trawler or small frieghter
doing the same on a reciprocal course would be nearly invisible to you
simply due to the fact that your radar's proximity alarm or "range
guard" or whatever they call it would not go off until the ship on the
collision course was on top of you...solely due to the mizzen
placement.


If the radar antenna were a point source of RF out and back, this might be
true. But, it's not a flashlight. The flat panel PC board planar array of
the 2KW Raymarine dome is about 2' wide. The whole panel radiates and
receives RF, so it's like having a set of "eyes" on the mizzen that are 2'
apart. Could you see around the mainmast to all targets, the mainmast
being 20' away from you with this "eye" arrangement? Yes, it works, even
on small bouys 3 miles away. I've swung the boat through each degree very
slowly to see if the bouy I could see off to the side had a blind spot dead
ahead. It didn't. The panel isn't a point source like a flashlight. It's
more like a 2' diameter floodlight shining past the mast, illuminating the
target dead ahead, but probably with some loss of efficiency.