I spent a bit of time in Santa Cruz, so I guess "buoy" came up a lot more often. I always heard it called a boo-ey, even by sailors. Maybe it's just Northern California? Although, as you said, while we up here call it a boo-ey, we still refer to boy-an-see, not boo-yan-see. But now, where does THIS come from? I've heard "boil" pronounced "bile". I want to say that's from deep in Dixie, but I'm not sure.