The piano on the sandbar
How did the baby grand piano wind up on a sandbar in Florida's Biscayne Bay?
Kind of like the way pianists get to Carnegie Hall, it turns out: Practice, practice, practice.
"Why?" gets you a more complicated answer.
The apparently definitive tale, from the Miami Herald:
http://www.miamiherald.com/2011/01/26/2036256/piano-mystery-solved-movie-prop.html