The Long Lake boater who was ejected into the air after his personal watercraft exploded Saturday afternoon has been treated and released from Bridgton Hospital.

According to Maine Warden Service spokesman John MacDonald, Karl Marchionda, 31, of Danvers, Mass., was thrown 20 feet into the air after pumping 10 gallons of fuel into his Sea Doo watercraft at Long Lake Marina in Naples.

MacDonald said Marchionda was seated on the watercraft at the time of the explosion and injured several ribs and vertabra after landing face-first on a dock. He was lucky, since he fell onto an adjacent dock, rather than in the water, said MacDonald. While the Sea Doo erupted in fire, Marchionda was not burned in the explosion. His injuries were considered non-life-threatening.

Marina owner James Davenport quickly extinguished the fire that had started in the hull of the Sea Doo. Early investigation by Game Warden Neal Wykes indicates that the explosion occurred as Marchionda attempted to start the Sea Doo.

“He tried to crank it over one or two times, and I think it was several tries into it that the thing exploded,” MacDonald said.

MacDonald said some of the fuel was diverted into the hull of the Sea Doo through a loose lock-ring that holds the fuel pump and pump filter in the gas tank.

“He filled it up, put the gas cap on, and Neal thinks that whatever seals it together had backed off, maybe by vibration, so that all of the gas didn’t go in the tank with some going into the hollow of the machine. And that caused some vapors… so we think the ignition of the starter caused the explosion,” MacDonald said.

MacDonald said the 10 gallons of newly pumped gas didn’t explode. The collected fumes and gas inside the hull, next to the engine, exploded upon ignition and forced the fiberglass Sea Doo into two pieces, with the top half flying 60 feet into the air while the hull stayed in the water.

The two parts of the watercraft are “mated to one another with a seam,” MacDonald said. “The explosion blew the top part of machine away from the hull. So it didn’t look like wrangled debris, there was a pretty clean break at that seam.”

Eyewitness information about the explosion was given by a Massachusetts state trooper waiting in his boat directly behind Marchionda’s Sea Doo. Another half-dozen people witnessed the explosion.

“He witnessed essentially the whole thing and provided a good statement for us as a firsthand witness,” MacDonald said.

Wykes said Marchionda didn’t remember what happened between the time the explosion occurred and he woke up to see several people gathered around him on the dock.

“He was doing OK, but he was pretty shook up,” Wykes said of his visit to Marchionda at Bridgton Hospital.

Wykes, who said he’s investigated only one other boat explosion in 31 years on the job, said Marchionda’s father owned the Sea Doo and that the father owns a seasonal home in Harrison.

Aiding the warden’s service after the explosion was the Cumberland County Sheriff’s Office and Naples Fire & Rescue.

Karl Marchionda’s Sea Doo personal watercraft exploded after the 31-year-old Danvers, Mass., resident pumped gas Saturday afternoon at Long Lake Marina in Naples. He was thrown 20 feet into the air. Investigators have determined the likely cause of the explosion was a faulty gas tank connection that allowed gasoline into the hull of the watercraft.