Winds up to 35 knots and seas up to 18 feet forced Hawaii Superferry to cancel its Maui voyages for a fourth straight day yesterday, but officials were optimistic service could resume tomorrow.

Such cancellations, especially in December when sea conditions in Hawai'i channels can be at their worst, were an anticipated part of the company's business plan, Terry Halloran, director of business development for Hawaii Superferry, said yesterday.

Still, hundreds of passengers with reservations had to delay their trips or make alternative travel plans as strong winds continued to whip up high seas in the Pailolo Channel between Maui and Moloka'i again yesterday.

"We're certified to operate in seas of up to 6 meters, but in the interest of passenger safety and comfort, we chose not to go on Saturday," Halloran said.

The strong trade winds and high seas are expected to gradually subside tonight into tomorrow, the National Weather Service said.

Superferry officials said they will modify the ferry's normal schedule tomorrow to start later than usual. A 9:30 a.m. departure from Honolulu Harbor will not only give more time for seas to calm, but also allow some passengers to fly ahead to pick up their automobiles, which have been stranded since the ferry service stopped on Wednesday, Halloran said.

A return trip to Honolulu is scheduled to depart Maui at 2:15 p.m. tomorrow.

While the company expected occasional cancellations because of weather, it had not anticipated they would come during the start of operations, Halloran said.

"It's very unlikely that we would have experienced these conditions in the summer," the original planned launch of interisland ferry service, Halloran said.

The company initially started service in late August but that was halted by legal challenges on Maui and protests on Kaua'i. It resumed Maui service Dec. 13, but has not set a date to restart service to Kaua'i, Halloran said yesterday. A second ferry is being built to expand service to the Big Island in 2009.

Company officials said fewer than 100 passengers were booked for travel yesterday and today. The company's Web site, www.hawaiisuperferry.com, yesterday said passengers booked on a canceled voyage would be contacted by a reservation agent to either reschedule the trip or obtain a refund.

To check voyage status for tomorrow and beyond, passengers should call 877-443-3779 and press option 1, then option 2, officials said.

The company also posts updates at www.hawaiisuperferry.com.

Reach Mike Leidemann at mleidemann@honoluluadvertiser.com.

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