The Coast Guard in Miami said it had received a report “from a good Samaritan” who rescued a man “clinging to a capsized vessel approximately 45 miles east of Fort Pierce Inlet.”
The survivor said the boat had left Bimini in the Bahamas on Saturday night but encountered rough weather and capsized.
“According to the survivor, no one was wearing a life jacket,” the statement said.
“Coast Guard air and surface asset crews are actively searching for people in the water. This is a suspected human smuggling venture,” said the statement, which was posted on Twitter.
Human smugglers are known to use the Bahamas, a group of islands lying near the Florida coast, as a jumping off point for getting people into the United States.
Bimini, the westernmost district of the Bahamas and its closest point to the mainland, is approximately 130 miles (217 kilometers) from Fort Pierce Inlet.