We heard from a British-born listener curious about the proper pronunciation of the word spelled buoy. In his boyhood home, he said, that name for a certain type of float is pronounced boy; the stateside pronunciation boo-ee sets his audio nerves on edge.
We don't want to get in too deep with watery allusions, but boy, what a difference an ocean can make. Our correspondent correctly observed that /boy/ is the more common pronunciation in British English. In American English, both /boy/ and /boo-ee/ are equally acceptable, but /boo-ee/ is predominant. Anglophiles can be buoyed, however, by the fact that /boy/ was probably the earlier of the two pronunciations.
However you say it, that four-letter word has kin in an early Germanic word that meant sign and that gave English the term beacon in the 14th century, 100 years after buoy first appeared in print.
By the way, although buoy and its linguistic relatives are the only English words to begin with the letters buo-, you can find a wide variety of buoys bobbing about the seas. They range from the anchor buoy (which marks the position of an anchor) to the whistling buoy, whose whistle is caused by the action of waves.