True story, and recent too.
A friend ordered the full suite of radar, plotter,GPS, LCD etc etc, all the bells and whistles. He opted for a gimballed radar mast mount. It all got installed and seemed to work fine and so he headed off to the West Coast and Barkely Sound.
After an uneventful but enjoyable couple of weeks there, he was sailing back through Juan de Fuca in lumpy foggy conditions. After a while he noticed that his radar overlay on the LCD plotter wasn't matching his track, and further, was nearly 90 degrees off. Cycle power, turned the boat played around a bit and no matter what the radar overlay was 90 deg out.
He finally thought to look aloft, and there was his radar, sitting nicely on the starboard spreader, pointing off the to left.
It seems the gimbal mount released, and due to the motion of the boat when the radome slipped off the gimbal, it got "flipped" up onto the spreader instead of dangling by the cable and bashing the mast.... lucky, what?
Anyhow a duck into Sooke harbour and an hour in the bosuns chair and he had it back together and temporarily lashed in place. The installer properly fixed it later.
Anyhow, probably due to sloppy installation in the first place, but it is another potential failure point.
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"