Jason Kopp, in hat, didn’t know much about boats when he purchased one more than four years ago. Now, he’s president of the Gangplank Slipholders Association.

It’s Thursday evening, and Laneyse Hooks, 54, climbs the stairs to her roof deck, where she grows corn and other vegetables, along with a variety of potted flowers.

Below, water laps at the base of her house, as the ebb and flow of the Washington Channel washes past the boats that the residents of a small community along Southwest D.C.’s waterfront call home.

“Our boat is basically like a condo floating on a barge,” says Hooks of the one-bedroom, one-bath vessel she shares with her husband and cat, for which they paid around $150,000. They named their well-lit housebarge Our Island.

Hooks is a native of Seattle, where houseboats are a common sight. She was drawn to D.C.’s Gangplank Marina, a community of houseboats that is the largest on the East Coast.

Visitors to the Southwest Waterfront can’t miss the marina, which stretches for a third of a mile along the waterfront, downstream from the Maine Avenue Fish Market and across from Arena Stage.

Of the Gangplank’s 264 slips, 92 are occupied by houseboats — also known as liveaboards. The fact that some people call the marina home barely registers with the District’s landlubbers. Not only do the majority of the houseboats not look like houses (most appear to be normal, recreational vessels, unlike Hooks’ housebarge), but the underdeveloped businesses along the riverfront — a hotel and a few restaurants — are ill-frequented by Washingtonians.

“I can’t believe it when I’m down here on a day like this,” Hooks says. “Look at it, it’s deserted.”

As evening arrives, Gangplank residents gather to grill and chat. The Mighty Seacocks, a rock duo composed of houseboaters, strikes up a round of covers on the bow of a boat across from Hooks’.

The residents of the marina are diverse in nearly every way — age, political outlook, socioeconomic status, race and profession. But a busy calendar of parties and events has made a tight-knit community out of this group. Tonight’s happy hour is a weekly event: It’s held every Thursday, often on the marina’s own party barge. On Sunday mornings, residents congregate, breakfast foods in hand, for Captain’s Coffee, an informal gathering on a small barge at the front of the marina or in someone’s houseboat.

“It’s a great social exchange, but it’s also really nice when you’re trying to work on your boat and you need advice,” says Jason Kopp, 32, who’s lived at the marina for four and a half years. “We actually depend on each other so much to help out with so many different things,” Kopp says.

It might be hard to guess that Kopp, now the president of the Gangplank Slipholders Association, had little experience with boats when he found his 40-foot-long vessel, the Argo, on Craigslist. He paid approximately $48,000 for it in 2007. Now, he pays a monthly slip fee of $10 to $15 per foot of length, along with a $150 liveaboard fee.

In the past few years, the number of liveaboard slips, which had been capped at 100, has slipped to 92 under a policy that says when a houseboat leaves the Gangplank, the liveaboard slip converts to recreational use. New residents can move in if they purchase an existing houseboat.

92 liveaboard boats or housebarges float in Gangplank Marina. This one, named The Timothy B, belongs to Susan and Joe Carpenter.

Many of the houseboats are capable of navigating the Potomac River or the Chesapeake Bay. Laura Rear McLaughlin, 33, and her husband, John McLaughlin, 35, purchased their three-bedroom, 2.5-bath, 47-foot Atlantic Motoryacht in Connecticut. The couple, both of whom work for the National Oceanic and Atmospheric Administration, cruised it from there to its new home at the Gangplank, where it replaced their previous, smaller vessel.

The boat, named Panacea, is spacious, with room enough to start a family. Of the three bedrooms, two are the size of walk-in closets, while the master offers a little more space. The walls are made of teak, which gives the interior a nautical feel. Panacea came with furniture optimized for boat living, including a kitchen table that can be turned into a bed.

It also has a washer and dryer. “We don’t have to use the marina laundry room anymore,” Rear McLaughlin says.

The marina’s shared laundry facility, which also has restrooms and showers, can become critical in winter, when many liveaboarders shrink wrap the exterior of their boats because of poor insulation. Removing sewage from the boats is impossible in freezing weather, so residents sometimes walk up to a third of a mile to use the shared baths, if only on the coldest days.

During pleasant weather, Diane Jones, 48, employed in regulatory affairs, sometimes works from the bow of her 36-foot catamaran sailboat, Concatamer II. She and her husband paid approximately $180,000 to live in the tight but sailable quarters. Its two bedrooms feel more like closets, with beds that tuck away to create more floor space.

“You have to really love your spouse, and you have to really like each other, too, because there is no alone time,” she says.

The same holds true for the marina at large.

As Laneyse Hooks takes in the evening amid her flowers and small plot of corn, the amped guitar and vocals belt from the neighboring bow, across the dock.

Inaudible, distant traffic on the 14th Street bridge races by upstream near D.C.’s iconic Fish Market. Farther north, the Washington Monument pokes above the rooftops of federal buildings.

On the riverfront, jazzy tinkling from a Thursday evening outdoor farmers market and concert put on by The Wharf is drowned out by distance as the Gangplank rocks out to its own funky tune.