Ari Fingeroth, aboard the Nauti Boat, a food boat that sells snacks on the Potomac River. Ari and his fiancee, Tammar Berger, launched it in the summer of 2014. (John Kelly/The Washington Post)

“Everybody’s in a good mood when they’re out here,” Ari Fingeroth says as we bob in the Potomac, just off the Georgetown waterfront.

A rower in a scull glides past Roosevelt Island, skimming the water’s surface. Just upriver, colorful kayaks swarm like dragonflies. A few cabin cruisers are anchored mid-channel beyond the Key Bridge, their skippers and guests enjoying an impromptu happy hour on a sweltering Friday afternoon.

I’m aboard the Nauti Boat, a pontoon boat that is one of the most interesting vessels to ply the Potomac. Think of the Nauti as a food truck on the water. Ari has hot dogs and ice cream, soda and lemonade. Sail up to him, and he’ll sell you a doughnut or a bagel or a chocolate-covered frozen banana.

This is the Nauti Boat’s second summer on the Potomac, and Ari is still a little surprised that he’s out here at all.

“It really started almost as a joke,” Ari says, adjusting the Nauti’s throttle slightly to keep the boat stationary in the gently flowing Potomac.

Ari Fingeroth looks out from under the Nauti Boat’s canopy while peddling snacks and beverages on the Potomac. (John Kelly/The Washington Post)

He and his fiancee, Tammar Berger, are boat people. They have other jobs — Ari does high-end home remodeling; Tammar works at the World Bank and co-owns a spin studio — but they really love being on the water. They keep a small ski boat at the James Creek Marina in Southwest Washington. They used to spend most weekends on water skis.

One day, Tammar craved a Popsicle. Wouldn’t it be great, she said, if you didn’t have to return to shore to get something to eat or drink? Why couldn’t a food boat come to you?

A lot of their friends told them it was the dumbest idea they’d ever heard.

Undaunted, Ari bought a used pontoon boat he found in Pennsylvania. He installed propane, a grill, a freezer, a fridge. He looked into how he might get permission to operate a food boat.

First he was told he needed to consult with the District Department of Transportation. Why? he asked. The boat doesn’t go on the road.

And so began a bureaucratic voyage that saw Ari checking in with numerous agencies: the D.C. Department of Consumer and Regulatory Affairs, the National Park Service, the Coast Guard, the Army Corps of Engineers, the D.C. police department’s Harbor Patrol . . .

Amazingly, none could figure out a reason to torpedo his plan.

“The whole project has sort of restored my faith in the D.C. government,” says Andrew Osterman, a friend of Ari’s who this Friday evening is helping crew the Nauti Boat, Tammar being out of town at a wedding.

Ari says: “I’m like an 8-year-old kid: ‘Why not? Why not?’ The guy at DCRA was very supportive once he realized I wasn’t going to give up.”

This summer, Ari added a Kegerator. He’d like to get permission to sell beer, but for now the taps dispense only lemonade and cold-brew coffee. (One sticking point in applying for a liquor license: where to post the notice inviting public comment? On a buoy in the middle of the river?)

Business is slow this Friday evening. There’s lightning off to the west. When the storm finally comes, Ari anchors under the Key Bridge, and we watch as rain soaks the passengers aboard the party-cruising Boomerang Pirate Ship.

Ari has an old salt’s familiarity with the denizens of the Potomac, a geographic feature to which the capital owes its existence but to which we often turn our backs.

The dragon boat people are great, Ari says, referring to those enthusiasts who paddle long, colorful canoelike craft in an annual festival. Kayakers are good customers, too. The hard-core rowers in their sculls and “eights” are a little too focused to stop for an ice cream.

Sometimes, Ari sells to the crew of the Firefly, one of the yachts that MicroStrategy chief executive Michael Saylor docks at Washington Harbour. D.C. Harbor Patrol officers have been known to stop for coffee, too. (The water cops seem supportive of Ari’s venture, though they’re against his getting a beer license.)

Ari can’t serve anyone on land or aboard the Nauti. Business must be B2B: boat to boat. That’s because of exclusive contracts other vendors have with the Park Service.

Sometimes, Ari anchors and waits for customers to come to him. Some tweet or text him orders. Sometimes he motors around. Maybe you need a bell, I suggest — like a Good Humor truck.

“We didn’t want to be too annoying,” Ari says. “And we didn’t want to hear it all day ourselves.”

Ari’s last customers are four people aboard a little powerboat. Three of them are visiting from Cleveland, and the boat’s owner promised to show them Washington from the river. Sustenance-wise, they seem to have packed nothing but a jug of vodka and a bag of cheese curls. They order a cup of coffee, a lemonade, a hot dog and a couple of veggie dogs.

Ari and Tammar won’t be quitting their day jobs anytime soon. They just hope to cover their expenses and spend more time on the water, floating far away from hard, unyielding asphalt.

Twitter: @johnkelly

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