There’s a home-made sign on deck 11 of Royal Caribbean’s Navigator of the Seas that reads ‘Super Mario’s Office’. Every morning, a dapper, tanned passenger perches there, quietly tapping away at his keyboard. An office corner rather than a corner office, this is the HQ for 65-year old Mario Salcedo’s investment management business—at least when he’s not ballroom dancing, scuba diving, or smoking a Cohiba in the cigar lounge on board. While for most people, a cruise might be an annual vacation, for Mario, it’s his everyday life. Though he keeps a condo in South Florida, Salcedo has effectively lived full time on a cruise ship for almost twenty years, making him part of an élite cabal of permanent passengers.

He didn’t initially intend to become a full-time cruiser. “When I hit 45, I wanted to start a new chapter in my life traveling around the world—that was my vision,” he explains, from onboard the Navigator of the Seas, en route to Grand Cayman. “But I didn’t know about the logistics, whether air, train, or sea.” Living in South Florida, he’d seen plenty of ships berthed at the Port of Miami, so he decided to start with a cruise—and never looked back. Salcedo shopped around, road-testing different lines until he booked a stint on Royal Caribbean’s Voyager of the Seas. “It was the biggest cruise ship in the world at the time, and so revolutionary—the first ice skating rink, the first rock climbing wall, so many elements that took cruising to another dimension,” Mario recalls. He has not stepped foot on another liner’s ship since and is about to celebrate his 6,000th night with Royal Caribbean—that is around 850 individual cruises. “Nothing could lure me away from them, because I get treated like royalty,” he chuckles, punningly, “The captains all know me.” Indeed, it was Liberty of the Seas captain Charles Teige who first called him Super Mario a decade ago, a nickname that’s stuck from ship to ship.

Salcedo has effectively lived full time on a cruise ship for almost twenty years.

Salcedo budgets around $60-70,000 per year for his travels, paying for the voyages by credit card so that the miles earned will cover any flights in between sailings—if he lived in London, of course, that could be a saving on his regular rent. He books an interior stateroom—“I don’t do anything in my cabin other than shower, get dressed and sleep,” he says—and schedules trips around two years or 150 bookings ahead. That way, he can remain in the same room for an extended period of back-to-backs, as continual sailings are known. Usually solo travelers like Mario are charged a 200% single occupancy supplement, but thanks to his status in Royal Caribbean’s Crown & Anchor Society loyalty club, he’s only levied 150%. And though most cruisers gain around a pound a day when sailing, Salcedo has remained trim. “I don’t eat like a regular cruiser. I skip one meal a day, and eat smart,” he says. “I do lots of dancing and walking. I only put on a couple of pounds when I’m on land eating at McDonald’s and Burger King.” Otherwise, on port days, he skips most excursions, preferring to indulge his passion for scuba diving. Sea days are his favorite, since they’re a chance for the night owl to make new friends. “I go dancing in the lounges, or enjoy a nice cigar after dinner with a cognac, watching basketball or football games on TV. Everything I do on the ship provides an opportunity to socialize.”

Salcedo’s most memorable trip was a 72-day crossing on Voyager of the Seas from the U.S. to China via the straits of Gibraltar and the Suez Canal with port days including the Canary Islands, Egypt and Israel He wanted to travel with that ship, his first love, to its new home port of Shanghai. “I decided not to get off the ship when it arrived, and booked two back to backs with 3,000 Chinese people, just to see what it would be like,” he says. “I felt like a fish out of water, and it was the only cruise I’ve ever done when I never spoke to a single guest. But there were so many interesting ports of call—Vietnam, Indonesia, several stops in Japan.” He doesn't suggest a cruising newbie book such an outré adventure; instead, Salcedo recommends a transatlantic crossing for first timers, from Barcelona perhaps or Southampton. “Those are my favorite itineraries when you get the real flavor and romanticism of the seas.” (As a bonus tip, he suggests westbound journeys, when the clock adjustment offers an extra hour in bed every morning.)

As for Salcedo himself, he only logs 15 days or so on land every year, almost all of them isolated one-offs when he’s flying between ports or spending a day filled with appointments at the doctor or the bank. He never overnights at the two-bedroom condo he’s retained in Miami as his base—one bedroom’s been co-opted into what Salcedo calls a "cruise museum," full of memorabilia from his various trips on Royal Caribbean’s ships. It’s only when he’s there, though, that he experiences the sole downside to his full-time life on the high seas. “I’ve lost my land legs, so when I’m swaying so much I can’t walk in a straight line.”