Scudding through New York Harbor amid bobbing sailboats, looming fuel barges and the orange-hulled Staten Island Ferry, Brian Cohen’s $2.5 million Gunboat 55 catamaran CTRX +% is an island of calm. Guests sip a crisp Sancerre at a table in the yacht’s teak-decked salon as Cohen steers the boat downwind toward Manhattan. The stiff sea breeze quickly propels the 55-foot Rainmaker past 16 knots, or 18mph.

That would have been a terrifying speed in Cohen’s old sailboat, a single-hulled Swan 40 racer, the type that used to set the standard for performance sailing yachts. But it’s half the top-end speed of Rainmaker, a luxury cruiser that shares much of the lightweight, carbon-fiber technology that propelled Larry Ellison’s twin-hulled catamarans to victory in the most recent America’s Cup.

“What I love about this boat is it’s so disruptive, in so many ways,” says Cohen, a 59-year-old Boston University-trained journalist who made his money on the personal computer revolution in the ’80s and ’90s, then doubled down as an angel investor–famously, he was the first to invest in Pinterest.

From the 78-foot mast to the lithium batteries in the bilge, Cohen’s Gunboat 55 represents an assemblage of technology that was practically impossible to obtain 20 years ago. The enormous mainsail, 1,300 square feet of high-tech fabric, has a computer-designed shape that can handle a much broader range of wind than old-fashioned Dacron sails. The hulls and 200-square-foot bridge are made of carbon fiber and epoxy to achieve the strength and stiffness necessary to haul two luxury staterooms with en suite bathrooms, plus amenities like a fresh-water maker, a freezer and a washer-dryer. The cabin top is covered with solar cells that help charge an 800-watt electrical system that powers computer navigation screens, electric winches and a cranking marine audio system.

Johnstone, whose father and uncle designed the J/24, one of the most popular sailboats ever built, says he was “banished” from the family business at 19 because he “had too many ideas.” He started building lightweight, high-performance dinghies in the 1980s, later sold his company to the Johnson family of S.C. Johnson fame and caught the multihull bug sailing with the late Steve Fossett on his 105-foot trimaran PlayStation. He built his first Gunboat–the name refers to the cannon, or “gun,” that salutes the first yacht over the finish line–in 2002 in South Africa.

“For the first seven or eight years people talked to me like I was nuts,” Johnstone says. Now owners include Austin Hearst, with a 66-footer named Slim, and the rear commodore of the New York Yacht Club, Phil Lotz, who has a Gunboat 60 on order. So it’s not unreasonable to imagine the nation’s second-oldest yacht club, founded in 1844, will have a Gunboat as its official flagship in a couple of years–no doubt an unthinkable development for many of the club’s tradition-bound members.

As for Cohen, he plans to proselytize about the merits of carbon fiber and twin hulls all summer in New York, then take Rainmaker down to the Caribbean for the winter. With 11 of the 55-footers and 8 of the Chinese-built 60-footers under contract, Cohen’s Gunboat soon will have plenty of company in New York, Newport and other ports where sailors are increasingly turning to high-speed luxury yachts. Meanwhile, Gunboat is working on a 72-foot series as well as a 40-footer equipped with the curved foils that lifted last year’s America’s Cup cats out of the water and helped them accelerate past 60 knots. But that speed might topple a martini.