Crews responded to a boat on fire off Biscayne Bay Thursday afternoon.
Aerial footage from NBC 6 showed think black smoke and flames coming from the 46-foot vessel as a Miami-Dade Fire Rescue fire boat worked to put out the blaze.
Four men were on the boat and one of them said they had been out for about 30 minutes when smoke started coming from the hull.
The men tried to fight the fire with buckets but it was too much for them to handle. They put life jackets on, called for help and were rescued by a good Samaritan.
"First tried to put it out, fire extinguishers weren't working. It didn't help, the fire spread and poof, the whole ship went down," passenger Robert Johnson said.
As firefighters were putting out the flames, the boat sank about three and a half miles from shore.
"They're lucky to be alive, dead honest, very very lucky to be alive especially in a situation like that," said Burt Korpela, a salvage captain who brought them to shore.