Cellphone video captured firefighters hosing down the burning vessel at The Yacht Club at Marina One along North Federal Highway, Saturday afternoon, as heavy black smoke billowed into the air.
Witnesses said there was an explosion on board. However, officials have not confirmed these reports.
Video also showed police officers blocking the entrance to the marina while they investigated.
It remains unclear whether the victims were taken to a hospital. Their conditions are unknown.
Officials said up to 40 pounds of fuel leaked into the surrounding water.
There is no word yet on what may have caused the fire.
Crews are currently working to clean the fuel spill.