Thirteen of 59 commercial sailing vessels operating in Hawai'i were found to have had mast problems, including corrosion, fractures and missing bolts, and were temporarily taken out of service after a round of inspections last summer, the Coast Guard recently revealed.

Most of the catamarans and trimarans with what the Coast Guard called "serious safety deficiencies" were repaired and returned to service, but two went back to sea on engine power alone minus their mast and sails, officials said.

The special inspections were ordered following two fatal catamaran accidents less than four months apart in Hawai'i and raise anew the issue of safety on the popular tourist boats.

The Coast Guard is finalizing investigations into the cause of mast-related failures on both of the catamarans.

The summer inspections were made in addition to annual safety inspections that are conducted by the Coast Guard, officials said.

A 65-foot mast came down on the Na Hoku II off Waikiki in December 2006, killing a 13-year-old boy, seriously injuring two women, and slightly injuring several other passengers.

A year ago this month, a 48-year-old father of three was struck and killed by a falling mast and rigging aboard the Kiele V off Maui. Two other passengers were injured.

"We stepped forward and worked with these commercial sailing vessels and came up with a better plan," Coast Guard Lt. John Titchen said of the safety inspections. "We didn't want to wait for the investigation. Nor did we want to wait for anything else to happen."

Titchen said the additional checks are "another layer of safety that we've added."

Asked about the safety of tourist catamarans here, Titchen said: "I think it's like everything else that you do — you have to be aware of the circumstances and the consequences and we hope that our sailing vessel operators out there are as safe as they possibly can be. We are going to give them the tools to do that."

BOATS CALLED SAFE

Tour operators say the catamarans are safe and are closely monitored by the Coast Guard. One raised concern about metal parts manufactured overseas that may be more prone to failure, though.

"The only thing I know about are the seven vessels on Waikiki Beach, and from what I know of every owner — and I know all the owners — everything is top notch," said Bob King, managing director for the 45-foot Outrigger catamaran.

King said he spent close to $200,000 last year on improvements, including replacing the "beams" on the former racing catamaran — the transverse struts that connect the pontoons.

The Outrigger was inspected by the Coast Guard no fewer than three times in 2007. King raised concern about the use of foreign-made metal parts on some boats.

"We don't use any foreign aluminum or metals on our boat whatsoever," King said. "What you have is a lot of aluminum or metals coming in from foreign countries, and when you have that happen, you don't have the same quality standards that you do in the U.S."

King said a friend with a sailboat had a failure of a Chinese-made shackle that caused the loss of his mast.

WEAR AND TEAR

Titchen said the 11 commercial catamarans found to have had "serious safety deficiencies" over the summer had masts that were still structurally sound, but to the point "where if it went unchecked, it could then down the line be a significant issue." The deficiencies were not abnormal given the wear and tear the boats experience, he said.

The two fatal accidents, meanwhile, "highlighted a need for further preventative action by boat owners and operators," he said.

The investigations by the Coast Guard into the two fatal accidents could lead to changes nationwide for commercial catamaran operators, Titchen said.

According to the Coast Guard, Hawai'i has the most tourist catamarans in the nation and its territories, followed by Puerto Rico with about 30.

About a dozen tourist sailboats operate in Gulf Coast states, an equal number are found on the east coast of Florida, and about a half-dozen ply the waters off California, the Coast Guard said.

Marine experts say mast-related failures on sailboats are nothing new; what was different in the 2006 and 2007 cases was that they caused fatalities.

Mike Doyle, a marine surveyor with 35 years of experience in Hawai'i, said he's aware of more than 200 "dismastings" involving monohull and catamaran sailboats here. Some of the masts were wood and most were aluminum, he said.

However, the Coast Guard said a check of its records showed no fatalities involving commercial catamarans in Hawai'i before the 2006 and 2007 cases.

Doyle said a piece of rigging sometimes fails and the mast cracks and falls overboard. But he believes the mast "step," or base, failed, and the mast jumped off the step during the two catamaran fatalities.

"I think what's happening on these catamarans is they are flexing more than people realize," Doyle said. "I think these problems, corrosion or some other problems developed, where the mast then was not properly supported."

Titchen said both masts in the fatal accidents were metal. King, on the Outrigger catamaran, said he uses a balsa and fiber mast, "so we don't deal with those corrosion issues."

EARLIER DEMASTINGS

The last serious demasting of a commercial catamaran before the two fatal accidents involved one of the same catamarans — the Kiele V, the Coast Guard said.

No one was injured in the two previous Kiele V demastings, one at sea in 1991, and one in dry dock in 1996, according to records.

The Hyatt Regency Maui Resort & Spa operated the Kiele V. Chris Martello, a spokeswoman in California, said the catamaran no longer operates in Hawai'i.

The owner of the Na Hoku II, which did return to business, could not be reached for comment.

According to the Coast Guard, of the 59 commercial catamarans and trimarans operating in Hawai'i, 16 are based out of O'ahu, 21 out of Maui, 12 out of Kaua'i and 10 out of the Big Island.

The Coast Guard's Titchen said most investigations are completed within a year to a year and a half. It's now been 15 months since the Na Hoku II accident.

The Coast Guard is very deliberate with the results because "a 20- or 30-page document could change the law in terms of how these vessels operate," he said.

King, who operates the Outrigger, said the Coast Guard cracked down on safety after the two fatalities. "We felt it. Everybody did," he said.

"There's a lot of safety down here. None of us want to see somebody get hurt," King added. "Safety is first and foremost. Not only do we not want to hurt somebody, but we don't have a business if we do something that is going to endanger somebody's life."

Reach William Cole at wcole@honoluluadvertiser.com.