A traditional Hawaiian blessing was held yesterday in Mobile, Ala., marking the start of construction for the first of two 345-foot ferries that will transport passengers, cargo and vehicles around the islands in about two years.

"Hawai'i will soon benefit from an energy-efficient, environmentally friendly, convenient and economical sea-transportation system," said Timothy Dick, chairman of Hawaii Superferry Inc.

Construction of the state-of-the-art catamarans — the largest aluminum vessels ever built in the United States — is starting six months earlier than scheduled. They are being constructed by Alabama-based Austal USA for $75 million each, Dick said.

The first ship is scheduled to ply the seas in mid- to late 2006 with the second one to follow 16 months later.

Austal USA chief executive Greg Metcalf said the design of the ships, which is based on a similar vessel it built for the U.S. Marine Corps for use in the Pacific, was selected by Superferry for its comfort and sea capabilities.

Dick said a ferry system could boost Hawai'i's economy and change the business climate — helping everyone from local farmers to contractors.

"I think it will make Hawai'i significantly more competitive as a state," he said. "Anytime you can take friction out of the transportation system you are fundamentally lowering the cost of the goods and services.

"It's exactly the same thing as the Internet, but we're moving butts and boxes instead of bits," he said.

Leroy Laney, an economics and finance professor at Hawai'i Pacific University, said having another transportation option is good for Hawai'i, if it is profitable and self-sustaining without public subsidies.

"I don't know about the ferries transforming the economy, but I do think it would be an alternative to air transportation, which has a monopoly," he said.

The four-story vessels, each about the size of a football field, can transport 900 passengers and up to 280 vehicles. They travel about 45 mph, making trips from O'ahu to Maui and Kaua'i in about three hours and the trip from O'ahu to the Big Island in about four hours.

Flights between the islands usually average about 30 minutes to 45 minutes.

"I think the losers would be the airlines, obviously, and then possibly rental car companies if you can take your own vehicle," Laney said. "It would be some kind of competition for the airlines, especially if the fare is cheaper."

Dick said he doesn't think the ferries will hurt the interisland airline industry.

"I think we're much more a complement to the airline industry," he said. "They have a fast and frequent service we won't be able to match, obviously."

He said rising interisland roundtrip airfares and heightened security at airports may have prevented people from traveling, suppressing the interisland market.

"If we can bring back low-cost interisland travel so people can visit their friends and relatives on Neighbor Islands, I think we will see more (travelers) come back, absolutely," he said.

Dick said it might change the way people rent cars, but not necessarily hurt the industry. Instead of a tourist renting a car on each island, they can rent a car on one island and keep it with them longer, Dick said.

"It changes the game a little bit, but we don't think it changes the overall demand," he said.

Tickets for the ferry service will cost about half that of an airline ticket, Dick said. Bringing a vehicle will cost about the same as a passenger.

Unlike the commuter ferry system in Seattle, where passengers purchase tickets before boarding, Hawaii Superferry customers will buy tickets in advance by phone or over the Internet, similar to booking a flight.

"In Seattle, if you miss one ferry, you have half an hour and you get the next one," he said. "That's OK if the voyage takes 15 minutes. It's not OK if the voyage takes three hours in each direction and the ferry won't be back for seven hours.