Info on Coot class boats?

[RustyL]

When I first started to sail with my parents as a teenager (early 60s), we had a clinker-built (lapstrake) dinghy with a massive cast-iron centerboard called a Coot, I believe about 15 or 16 feet long. There were several of these boats in the club, so I know it wasn't a one-off design. I recently wished to look up some technical and/or historical info on this design, but found that a Google search turned up zilch (other than plans for an old C. B. Sharpie named "Coot").

Would anyone here know anything about the design? I believe the original came out of England. It was famous for this: on a broad to quarter reach, when the trim was just perfect, the centerboard would hum loudly, loud enough to be heard by other boats nearby - cool, yeah?