6 Aboard Power Boat Survive Explosion : Escape: Owner and five guests jump to safety, swim to shore and watch 17-foot vessel burn. No one is seriously injured.

A 17-foot power boat exploded into flames in Newport Harbor on Saturday afternoon, prompting the owner and five guests to dive overboard, authorities said.

No one was seriously injured, although flames consuming the vessel just 50 yards from the dock near the Balboa Pavilion created a spectacle for passersby.

Gary Nelsen, a 40-year-old Balboa Peninsula resident, was taking the Silverline inboard-outboard on its first spin since he recently inherited the vessel from his father. He said he had planned to treat five friends, two of whom were visiting from Arizona and San Diego, to a harbor tour and water-skiing excursion.

But they had barely left the dock at 3:20 p.m., he said, when the boat blew up. He said he has no idea what caused the explosion. He noted that the boat had been in his family for 20 years. Just minutes before, he said, he had filled the tank with 20 gallons of gasoline.

“It was burned to a crisp and sinking within two or three minutes,” he said. “We were lucky nobody was killed.”

At the time of the explosion, Nelsen said, he was just putting away the docking line.

“I saw two of my buddies flying off the back seats into the air,” he said.

After trying futilely to beat the fire out with a towel and to rescue his friends’ wallets from the flames, Nelsen said he decided to join the others in abandoning ship.

“We swam to shore and sat there and just watched it burn,” he said.

Four of the passengers escaped with no injuries. But one, Kevin Stone of Scottsdale, Ariz., lost a couple of teeth and suffered first-degree burns on his face and a leg, Nelsen said. He went to a local hospital for treatment. The fire singed the hair off the legs of another passenger, Nelsen added.

About a minute after the explosion, Orange County Sheriff’s Harbor Patrol deputies arrived to put out the fire and tow the charred boat back to the docks.