The chief financier behind Hawaii Superferry's plan to begin interisland runs by July 1 thinks the service has enormous potential to reshape local travel plans and make a solid profit at the same time.

John Lehman, a former secretary of the Navy who now heads an investment company supplying up to 70 percent of the Superferry's financing, said yesterday that he sees a sound financial business plan based on heavy use by local residents, including farmers and other small entrepreneurs.

"They'll be the heart of our business," Lehman said in a discussion with Advertiser editors. "It will be families, the small business people, and the truck farmers who will benefit the most."

Lehman, whose J.F. Lehman & Co. private equity firm specializes in maritime and aeronautical investments, said Superferry's plan and potential for growing and reshaping the Islands' transportation industry convinced him that it would be a good investment.

"It will be the businessmen and families with their cars, not the walk-on passengers, who will provide the bulk of our business," he said, adding that the company believes it can be profitable even if its ferries operate at less than 50 percent capacity.

Lehman was in Honolulu this week to meet with company officials and others, including some state lawmakers who are trying to delay the start of ferry operations by requiring an environmental impact study before the first sailing.

Although the state and two courts have ruled that the ferry operation is not required to do an environmental study, two bills are moving forward at the Legislature to require just that.

Critics have said the new ferry operation could have an adverse impact on harbors, the transportation of invasive species, local traffic and migrating humpback whales.

Lehman said the company has gone far beyond state and federal requirements in its environmental planning and protection efforts.

"We knew we were the new kid on the block and everything we did would be scrutinized closely," he said. "That's why we have in-depth volumes of all our environmental work to deal with these issues and protect the environment.

"We support the environmental impact studies in principle. But it is grossly unfair to single out one company for an EIS. We think the way to do it is require an environmental study for each port in Hawai'i as part of the master plan process."

The company recently submitted an operating plan required by the state Transportation Department and hopes to have its first ship in Hawai'i by early May to begin sea trials here, Lehman said.