Flames Engulf Sailboat Off Newport Coast : Rescue: Five passengers safely flee to a smaller craft they were towing. Party fishing on a nearby yacht guides fireboats to the blaze, which took 30 minutes to put out.

A 56-foot ketch sailboat headed for Santa Catalina Island was destroyed by flames off the coast of Newport Beach at dawn Saturday, forcing the family on board to flee to a smaller skiff they were towing, authorities said.

The boat’s owner, Thomas Hogan, and four other passengers were not injured and were rescued after another boater called for help. The fire gutted the sailboat, named the Bonhomme Richard, and spread so quickly that passengers could not reach the boat’s radio.

“All that’s left is a little bit of the hull,” said Royal Radtke, a bank manager who was on a nearby yacht and spotted the flames through the fog. “I sail a lot and I’ve never seen a sailboat so engulfed in flames. This was the real thing.”

Hogan, 48, of Newport Beach was about a mile off Newport Harbor about 6:30 a.m. when he spotted smoke coming from the boat’s motor, said Sgt. Mike Hiller of the Orange County Sheriff’s Department Harbor Patrol.

When Hogan removed the motor’s cover to take a look inside, exposure to the air caused the smoldering engine to burst into flames, Hiller said.

“He tried to put it out with two small fire extinguishers, but it didn’t work,” he said. “The smoke filled the cabin so quickly he couldn’t reach the radio to call us.”

A group of people fishing on The Bounder, a three-story yacht belonging to Newport Beach millionaire John Crean, were among the first to spot the fire.

“John said, ‘Oh my God. Flames!’ ” Radtke said. “He immediately took charge of the controls and I grabbed the life preservers and we took off.”

Hiller credits occupants of The Bounder with calling for help and guiding two fireboats to the scene. The boats arrived eight minutes after receiving the 6:56 a.m. call from The Bounder.

“They gave us a great location. When we’re in the fog we can’t just go out and start looking,” Hiller said. “They helped us go directly to the boat.”

Radtke said Hogan, his wife and three other passengers believed to be family members were already on board a small Boston whaler watching the sailboat burn. Both masts fell to the ocean in flames, Radtke said.

Hogan could not be reached for comment Saturday and the names of the other passengers were not available.

Hiller said the family was wise to board the 17-foot skiff they had been towing behind the boat and cut loose, instead of staying on board to battle the flames.

“They did the right thing,” he said. “It was very intense. It took us about 30 minutes to put the fire out.”

The 30-year-old boat was valued at $250,000, said Hiller, who added that an exhaust pipe likely started the blaze.

“It is a common occurrence with boat fires,” he said. “There’s heat-resistant material around the exhaust pipe that doesn’t get repaired or it burns away and then it’ll start cooking the wood over time.”