Police and firefighters were called to reports of an explosion on Bulkhead Road in Green Cove Springs just after 5:30 p.m.
Police said crews arrived to find several people in the water at Reynolds Park and multiple boats on fire.
Stephen Glover, 53, and Randall Thompson, 66, had turned off their boat's electricity to work on a fuel leak. Glover said while the electricity was off the bilge pump may have kicked on, causing the fire and forcing everyone to jump into the water. Within minutes, the fire spread to four other boats.
Those boats are now deemed a total loss and are inoperable, according to the state fire marshal.
"While they were working on the boat they heard a loud pop and then they were surrounded by flames forcing them to jump off the boat and into the water," Kimberly Robinson with the Green Cove Springs Police Department, said.
Former U.S. Navy firefighter John Jarvis said he was eating dinner on his boat at the marina and heard the explosion and knew what he had to do.
“I ran down here as fast as I could, and I started yelling to push the boats away,” Jarvis said. “When you get this bad a fire, and you can't put the fire out, then you have to break the fire triangle up, they call it.”
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Although the boats are charred and hardly recognizable, Jarvis said he's just glad he was able to jump in at the right time, getting the victims to safety.
“Everybody worked together, and all the group down here worked together, and got these boats out and retied down there, because the owner of the Valiant, he's in California,” Jarvis said.
Both Glover and Thompson are expected to make a full recovery. Officials said the cleanup will take a while, and may have to bring in a crane to lift the boats from the water.