What began as a farewell sail for the son of a Hawaii island resident turned into a floating inferno that forced both men to leap overboard south of Oahu.

Ronald C. Woodard, 67, of Waikoloa and his son, Ronald Jr., 31, were rescued from the ocean Thursday roughly 1,300 yards off the Ala Wai Small Boat Harbor.

The 62-foot ketch Keaoleleana, estimated by its owner to be worth $1.8 million, sank in 800 feet of water, said the elder Woodard.

Interviewed on shore, Woodard said the vessel, which was made of teak and featured a whirlpool hot tub, was insured for only $500,000.

"I’ve lost a lot," Woodard said.

Woodard Jr. had a slight rope burn on his finger and paramedics wrapped his left arm, where he had received an earlier skin graft.

That was the extent of the injuries.

"I’m fine," Woodard Jr. said. "I’m completely fine."

Woodard Sr., who stays aboard the boat at the Ala Wai when he visits Oahu, said the two decided to go on a sail before his son left for China.

"We were just sailing and having a good time," he said.

He said he and his son had been out for an hour and a half and were returning from Diamond Head when the fire broke out.

Fire Department spokesman Terry Seelig said the men heard popping sounds and saw smoke from below but there was no explosion.

Woodard Jr. grabbed a fire extinguisher to try to put out the blaze.

But when the fire got too big, the men jumped off the ketch, he said.

Dive boat captain Randell Albertson said he was taking customers out on the Snoopy V when he saw smoke coming from the Keaoleleana, a half-mile away, and headed over to lend assistance.

Albertson said the sea was calm and the two men were in the water.

"They were hanging on to their life vests," he said.

Crew member Marco Dickson jumped into the water to help the men get aboard the dive boat.

The Honolulu Fire Department vessel Moku Ahi was called to put out the blaze, which quickly consumed the sails and toppled the masts. A dark gray plume was visible from most of Waikiki and Ala Moana Beach Park.

Seelig said the fire was under control by 2:02 p.m., about 39 minutes after the initial dispatch.

The fireboat was still shooting water at the smoldering remains when the Keaoleleana sank.

Woodard said he wasn’t sure what caused the fire but that the batteries recently had been replaced.

"It could have been the batteries," he said. "It could have been a short."

Hawaii News Now video: Sailboat burns off Waikiki; Father and son jump ship