LeDuc, 60, is captain of the tugboat Independent - home port: Tampa.

``If I should retire in about 10 years, I probably wouldn't be able to stay away,'' he says, leaning on a rail at the Independent's bow. ``I grew up at this port. It has given me a nice life.''

Beyond LeDuc, a blur of commuter traffic whizzes over McKay Bay via the 22nd Street Causeway - cars, sport utility vehicles, pickups and trucks. Many travel the causeway daily and, in their hurry, barely see what they pass.

Upon the tangy salt air ride the fragrances of a busy harbor - whiffs of diesel fuel, grease, metal, mud and creosote- soaked wood, mingling with the sharper odors of decaying seaweed and fish.

Machinery whines. Men shout. Engines rumble. And every so often this cacophony is punctuated by the sharp clang of metal striking metal or the earsplitting bass of a big ship's horn.

This is the broad back upon which Tampa raised itself, the Port of Tampa, where morning, noon and night the city's heavy lifting is done - a place dominated by oceangoing ships, wharves, warehouses, tank farms, terminals, dry docks, rail spurs, grain elevators, trucking operations, scrap metal yards, and cement, gravel and asphalt facilities.

It's also where Tampa might one day recast and revitalize its long relationship with the water.

LeDuc found his calling in this gritty place as a youngster working nights, weekends and summers alongside his father, who was a tugboat captain before him. After learning firsthand of the water's fickle nature and seductive appeal, he became a captain at 19, married and passed the trade on to two of his three sons, also captains for Marine Towing of Tampa Bay.

``The Bay is so beautiful with the lights shining on the water,'' LeDuc says. ``I can truly say I enjoy my job, and I know how important that is.

``When your life has nothing to do with the port, I can see how you don't think much about it. But it has an effect on everybody.''

It's an effect worth billions.

Growth Continues

The port is Florida's biggest, and the 12th busiest nationally - a world within a world that gives hundreds work and, according to port figures, generates more than $10 billion a year in revenue and $13 billion a year in spending across the metropolitan area. That makes it Greater Tampa's biggest economic engine.

About 800,000 cruise passengers pass through it every year on their way to or from such places as Mexico and the Caribbean, up from 500,000 in 2001. It also handles 50 million tons of cargo a year, half the statewide shipping volume.

There's every reason to believe that these numbers will keep growing. Business leaders are counting on Tampa to become increasingly important as a gateway for trade with countries in Central and South America and the Caribbean. (In particular, trade with Mexico will probably skyrocket soon, experts say.) It's the closest major port to the Panama Canal. And its share of the cruise business is growing so fast that the port will probably add a fifth cruise terminal soon.

The Tampa Port Authority, created by the Legislature in 1945 when shipbuilding fell off after World War II and the port's future was uncertain, oversees this busy domain. It's spread over 5,000 acres encircling much of McKay Bay, the thumb-shaped basin at the northeastern tip of Hillsborough Bay, then reaching westward across the peninsula of Hooker's Point and northward along both banks to the far end of Ybor Channel.

The authority owns about half this land, making it the city's biggest landowner; businesses own the rest. In addition, its holdings include Channelside, a collection of shops, restaurants and other business next to The Florida Aquarium; a parking garage across the street; and several hundred acres at Old Port Tampa, south of the Gandy Bridge.

In all, the county tax appraiser's office says this land is worth more than $92 million, up from $16 million 20 years ago. Add buildings, equipment and other assets, and the authority's net worth jumps to $335 million.

Civic Duty

With the cargo and passenger business so robust, and the future so promising, why would the authority be moving into the business of waterfront landlord? Part of it has to do with the business practice of diversifying, the authority says. And part is just good citizenship.

``Most people see the port as a place where ships come in,'' says Joseph Diaz, a dentist who sits on the authority's five-member board of directors. (The others are real estate investor Gladstone ``Tony'' Cooper; Lance Ringhaver, owner of a Caterpillar dealership; Mayor Pam Iorio and Hillsborough County Commissioner Ronda Storms.)

But if the authority can do more, Diaz says, ``why not?''

Diaz and others on the board credit this view to a long-running dialogue about the need for a greater partnership between the region's public and private sectors. This conversation is one of the things people point to when they talk about Tampa standing at the threshold of a transformation.

``It's been slow in coming,'' Diaz says. ``But it's here.''

The authority is negotiating with Byrd Corp., a Clearwater developer, to build a pair of 30- story condominium towers on 3 1/2 acres next to Channelside, facing Channelside Drive. It's also considering a proposed $400 million high-rise development that would include the city's first five-star hotel. And developers are salivating over an additional 300 acres the authority owns elsewhere.

All this has made some of the port's tenants uneasy. Among them is Gulf Marine Repair Corp., which has a ship and barge repair facility on Ybor Channel. The authority is pressing it to relocate within the port.

``It has always been a tenant port,'' says Gulf Marine's president, Aaron Hendry. ``I don't think there's any tenants that are absolutely safe, though. I think [the authority] should closely consider both sides.''

It will, Diaz promises. ``We can't ever lose the view that a port's main role is pushing cargo across the docks.''

By the same token, circumstances change, Diaz says, and the authority can't ignore this.

Tension between the two sides reached the boiling point a few weeks ago. After tenants said the authority wasn't taking their concerns seriously, the port's acting director - who wanted the job permanently - fired the authority's lawyer and its real estate director. Critics accused him of trying to make scapegoats of the pair. The authority's board members demoted and replaced him with a retired business executive who agreed to serve until a permanent director is hired.

As for LeDuc, he finds the friction unsettling but trusts that the authority's priorities will stay the same.

``What's good for the port,'' he adds, ``is generally the right way to do things.''

Whatever happens, LeDuc believes, there will still be a place for tugboat captains such as his sons. Just as there always has been for him.

Reporter Shannon Behnken can be reached at (813) 259-7146.