FORT LAUDERDALE -- From her elegant 17th Street showroom in Fort Lauderdale, Joanne Lockhart serves an exclusive clientele of mega-yacht owners -- including a royal family -- with onboard luxuries such as Swarovsky crystal napkin holders by Isabella Adams, Robbe & Berking silver flatware and gold encrustation china by Raynaud.

The former yacht stewardess knows from experience that keeping a $2,000 sterling silver egg cloche in stock and coming though with quirky requests (like black toilet paper and matching Q-Tips) are vital for the success of Yacht Next, the interior design, decor and accessory business she opened in 2008.

“We’re doing fabulous. For starting a business when the whole world was taking a financial dip, I couldn’t ask for more,” Lockhart said.

The city’s “Marina Mile” -- the stretch along the 17th Street Causeway -- earns its name from businesses like Lockhart’s that flow from the mega-yacht industry. Fueling its success is the Fort Lauderdale International Boat Show, which opens Thursday.

Before the show ends Monday, more than 130,000 are expected to attend the 52nd annual event, which features 150-foot-plus yachts plus accessories, technology, boating seminars and, for the first time, a section for live-aboard trawlers.

Though the mega-yacht industry is relatively small, with only about 4,500 vessels worldwide, its economic impact is “enormous” said John Mann, incoming chairman of the U.S. Superyacht Association and owner of Bluewater Books and Charts in Fort Lauderdale.

Fort Lauderdale alone rakes in $10.4 billion of the state’s $18 billion in mega-yacht industry revenue. More than $400 million of that comes from the boat show, according to 2007 figures, the last year for which the show’s manager’s released statistics. Ticket sales for this year are up 8 percent to 9 percent over 2010 already, and exhibit space is completely sold out.

But the industry’s wake lasts long after the four-day extravaganza. Because Fort Lauderdale is a favorite winter destination for these 150-foot-plus yachts, dozens of South Florida-based ancillary businesses like Mann’s book-and-chart store and Yacht Next are alive and well.

“It’s critical that we have the yachters come here for refits, provisioning, shopping at nautical stores, dining in our restaurants,” said Mann. Boat show aside, every 150-foot vessel docked in the city for a month can produce an economic “trickle-down” of $500,000.

Maintenance, repairs and upgrades for mega-yachts can run as much as $5.2 million each annually, estimated Kristina Hebert, president of the 825-member Marine Industries Association of South Florida and the operations officer of Wards Marine Electric Co. in Fort Lauderdale.

“And that money goes to plumbers, electricians, carpenters, interior designers … the list goes on and on,” said Hebert, whose firm employs 50 workers. Overall, in Palm Beach, Broward and Miami-Dade counties, an estimated 134,000 jobs come from the marine industry.

Many of them are skilled tradesmen -- a draw for yachts in need of tuneups, said Kaye Poulos, assistant general manager of the multi-million-dollar operation at Rolly Marine boatyard. Over the past seven years, Rolly has paid out $50 million in payroll money.

“When the boats are in the shipyard, hundreds of workers who live here are put to work. And when the boats come in, the crews go out … they become tourists and they spend money,” said Poulos.

Some companies are tiny, like mom-and-pop store ENB International Services, where owner Emma Batiller sells phone calling cards, wires money overseas and ships supplies back home for crew members on stopovers.

Others employ dozens and serve even more. At International Yacht Training, 1,200 students annually sign up for courses from basic safety training ($895 tuition) to top-level engineering courses ($3,590 per student), said president Michael French, a former yacht captain. Subjects range from formal table dressing to international civil and criminal law.

And of course, both crew and yacht owners alike need sustenance.

At Waxy O’Connor’s Irish Pub, owner Mark Rohleder serves up meals and spirits to a revolving cast of international crew members, called yachtees, who pack the place to catch the latest rugby and soccer games on TV.

“Crews know where to go to relax, find out what’s going on in the world, and catch up with friends,” Rohleder said.

For yachters who like to catch their own dinner, Andy Novak, owner of LMR Custom Rods & Tackle, sells all the gear required. It doesn’t come cheap. The most popular items -- custom Kite rods and reels -- sell from $400 to $479.

Special requests are common, as well, said store manager Tommy Kopper.

“If they want a rod to match their boat or the color of their wife’s eyes, we do that too,” he said.