MIAMI BEACH, Fla. -- Two people were hospitalized Monday morning after they were trapped in the hull of a boat that caught fire at the Miami Beach Marina.

The fire began on a boat docked at the marina and spread to an adjacent boat shortly before 5 a.m.

Miami Beach firefighters said a boat captain with a small charter boat alerted them to the victims waving their arms from the portholes on the burning boat, yelling out that they couldn't breathe.

Firefighters cut a hole in the boat and gave both victims breathing devices until firefighters could rescue them, Miami Beach fire-rescue Division Chief Javier Otero said.

"We got those victims out after approximately 40 minutes," Otero said. "The boat was approximately three-quarters involved (in flames), so it's amazing that these guys survived."

Both victims were taken to Mount Sinai Medical Center in stable condition.

The fire spread to a second boat, the "Vera D," which firefighters said is totally destroyed. Witnesses said the occupants of that boat screamed for bystanders to help them put out the fire.

Fellow boat owners brought buckets of water and hoses in an attempt to save the boat before eventually giving up. Passengers on the "Vera D" escaped without injury.

The owners of a third boat named "Hope Floats" said wind spread the flames to their boat, charring it badly. The U.S. Coast Guard rescued those boaters.

Witnesses said they feared the fast-moving fire would ignite a fuel station on the dock.

Miami Beach police are investigating to determine if foul play was involved.