As the city looks to its rivers to ease traffic congestion on its roads, the president of New York Water Taxi, Thomas Fox, a gregarious, silver-haired Vietnam War veteran from Brooklyn, could stand to make a windfall as one of the primary operators of New York’s last underutilized transportation corridors.

“The rivers have been used for 12 millennia as the main means of transportation, commerce, and communication,” Mr. Fox, lounging porch side at his beachside home in Breezy Point, Queens, said. “You don’t have to maintain it, it’s open 24/7, and it’s never crowded.”

With more than 60 miles of New York City’s abandoned waterfront recently rezoned for recreation and residential use, the water’s edge is undergoing a dramatic transformation whose success will depend largely on creating access to mass transit for emerging neighborhoods far from the closest subway stop.

An estimated 12,000 new units of housing along the East River are expected to be occupied in the next five years, according to some estimates, and developers are aiming to partner with ferry operators to make their units more appealing to New Yorkers who might otherwise forgo breathtaking views if the apartments were inaccessible by transit.

As the waterfront changes, ferry operators like Mr. Fox, who for decades have played peripheral roles in transporting New Yorkers around the city, stand to play an important role in the future of the city’s mass transit web.

Mr. Fox, 60, who says he is addicted to “the beast of New York City,” has played a leadership role in the redevelopment of its waterfront for more than 20 years. He served as the first president of the Hudson River Park Conservancy in 1992 and served on the West Side Waterfront Panel in 1988, when he came up with the idea for New York Water Taxi.

Today, Mr. Fox wears his hair shaved close to his head, drives a silver Lexus, and rides a BMW 1200 LT motorcycle but claims his goals haven’t changed since his days as a self-described “long-haired, earring in the ear, radical urban greening guy” in the 1970s. He is still an environmentalist and an idealist, he said. He considers his 109 employees a large family, he said, and he expresses a youthful excitement about being in the right place at a time when he can help change how New Yorkers navigate their city.

Mr. Fox says his experience in Vietnam bred his lifelong commitment to greening urban areas. “I had been experiencing the world from an apartment building in Brooklyn,” he said. “Then I was in a tent living on the South China Sea, and everything was shades of green. It had an impression on me.” A botanist by training, Mr. Fox said he still considers himself an urban activist by trade.

Mr. Fox first started New York Water Taxi in 1997 but lasted for just two months. “I was undercapitalized and I had the wrong boats,” Mr. Fox said. Five years later, he teamed up with developer Douglas Durst, who has poured in $20 million to the ferry business since it began in 2002. It has yet to turn a profit.

High gas prices and operating costs have made New York’s ferry business a historically unprofitable venture. East River ferries were run by New York Waterway, Mr. Fox’s primary competitor, until 2002, when the company abandoned the money-losing service. The other main intracity ferry provider is run by BillyBey Ferry Company.

New York Water Taxi ridership has climbed to about 2,000 riders a day on weekends, Mr. Fox said, with the East River service stopping along the waterfront at Hunters Point, East 34th Street, Williamsburg, Wall Street, DUMBO, and Long Island City. Mr. Fox is hoping to win a contract with the city’s Economic Development Corporation that could subsidize the price of a ferry ride and allow riders to swipe a MetroCard to board a boat, an arrangement which would require approval from the Metropolitan Transportation Authority. Mr. Fox said the expanded and subsidized East River commuter service could serve about 4,000 riders in the first five years, a figure that he said is expected to more than double within 10 years.

Mr. Fox, who said he is likely competing against two other operators for the contract, submitted his application with eight local developers signed on, agreeing to help build ridership on the ferry routes. “Each deal with a developer would be different,” Mr. Fox said. “We would be involved during the marketing phase, and they could help us build ridership through direct financial subsidies.”

The city hopes to announce the winning bidder soon, a spokeswoman said. The expanded ferry network is expected to be operational by 2009, according to the city’s sustainability goals outlined in PlaNYC.

Mr. Fox’s vision for a revitalized, active waterfront is big, but some of his most important decisions are small, he said. “If we did anything right, it’s the yellow boats with the black and white checks,” he said. “I could have called the company ‘Aqua Bus.’ Who in New York would have ever taken the Aqua Bus?”