Mary Lou Smith of Panama City Beach, Florida, took top honors in the women's division of the contest, often nicknamed the "conch honk" -- and received a surprise proposal from fellow competitor Rick Race, her boyfriend of 2-1/2 years.
"He got down on his knees and he proposed to me onstage," said an emotional Smith after the competition. "At first I was at a loss for words, so I just blew the conch shell -- then I said yes."
A retiree who said her motto is "have conch, will travel," Smith impressed the judges with her long blasts on the fluted, pink-lined shell -- and her impromptu post-proposal duet with Race as the standing-room-only crowd applauded.
Blowing into the conch shell has been a Florida Keys tradition for centuries. Early natives from the Calusa tribe blew blasts to communicate over distance, and seafarers used the shell as a maritime signaling device. Today it's a symbol of the Keys, which are often called the Conch Republic.
Judges evaluated contest entrants, who ranged from young children to seniors, on the quality, duration, loudness and novelty of the sounds they made.
Other winners included Vinnie Marturano of Big Pine Key, Fla., whose performance included blasts, high-pitched squeals and a song excerpt.
The contest was conceived by the Old Island Restoration Foundation, founded in 1960 to advocate the preservation of Key West's culture and historically significant buildings.