On a springlike afternoon in early March, rowboats and oars gleamed with fresh coats of paint, waiting for the anglers that would soon arrive in droves to rent them, as they have for decades at Fletcher’s Cove.

Though the boats are likely to be ready for fishing season, the “floating” dock that’s supposed to launch them is another story. As the tidal Potomac River marched away from the shoreline that afternoon, it left the dock marooned on a mud flat, more navigable by muck boots than boat.

Longtime anglers remember when this wasn’t the case, when the dock and boats launched from it could float atop 10-15 feet of water even at low tide — and they could row into the nearby waters to fly-fish as they wished.

That was decades ago, before the unthinking creation of a man-made promontory just upriver that altered the Potomac’s flow — and has slowly but inexorably filled in the cove.

Fifty years later, the dock that serves as one of the District of Columbia’s few access points to the Potomac barely floats at high tide. Boaters can rent rowboats, kayaks and paddle boats from 7 a.m. to 6 p.m. — but the dock that conveys them is only floating about half of that time these days.

Anglers who frequent the spot fear it may be permanently lost before long. They and other stakeholders are raising money to remove the mound of dirt and return the river and their cove to an earlier state.

According to excavations, American Indians used Fletcher’s Cove long before it became popular among heads of state — presidents Kennedy, Carter and Clinton have cast lines here. The cove is just downriver from the Atlantic Seaboard Fall Line, where migrating fish “stack up like traffic on a Beltway,” as one Washington Post writer put it.

The boathouse there is the only one that offers rowboats for rent so near to the popular fishing grounds. Fletcher’s Boathouse rented around 16,500 watercraft last year, and fishermen are known to share the boats.

As the fish arrive this spring, the two-dozen rowboats available for rent will be filled with anglers vying for the striped bass, white perch and shad that venture up the river to spawn. This stretch of the water also sees its share of small- and large-mouth bass and snakeheads.

Like thousands of other anglers based in the DC area, Mike Bailey has fished out of this cove for years. But it means more to him than most: He and his wife exchanged marriage vows on the floating dock.

“There’s no better place to fish in this area than Fletcher’s Cove in the spring of the year,” said Bailey, who helped form the Friends of Fletcher’s Cove group in late 2014 to save it from an uncertain fate.

“There’s something that’s so difficult to describe until you get here,” Bailey said, standing on the dock to point out the promontory that threatens it. “You can get an idea of the magnitude of it, how the river would normally flow through here and scour out the cove.”

But the river that roars by just beyond the cove during heavy rains now simply deposits more silt in the cove. In the mid-1960s, contractors working on sewage pipelines and other projects dumped massive amounts of excavated dirt along the bank just to the north. Today, the headland reaches 20 feet above the water’s surface and juts into the river.

“Without that impediment, this cove would not be collecting all this sediment,” said Art Noglak, fishing manager for one of the half-dozen Orvis retail stores in the Washington area.

If unimpeded, the river’s seasonal floods would normally flush silt from the cove, anglers say. Now, the water just swirls slowly in the cove, leaving sediment behind.

“It was something they could get away with in the mid-’60s. We don’t have a guilty party,” Bailey said.

A couple decades after debris created the embankment at Fletcher’s Cove, it became clear that the pile of dirt had permanently changed the river’s hydrology.

By the 1980s, the cove had become so silted in that it was sometimes inaccessible to boats at low tide. It was dredged in 1986, and a channel even cut through the headland with hopes of restoring the river’s flushing effect to prevent more sediment buildup.

It didn’t work. In the mid-’90s, they had to dredge again.

“We’ve been chasing the river ever since,” Bailey said. The floating dock has been moved farther out into the river as the cove became shallower.

The problem came to a head again at the end of 2014 when the National Park Service, which owns the property as part of the Chesapeake & Ohio Canal National Historical Park, closed the dock for the winter two weeks early because of safety concerns. Driftwood and silt had collected under the wooden walkway that connects the dock to land, and it was tipping to one side.

Bailey said the C&O Canal Trust and the park moved quickly to fix the dock as a temporary solution so it could reopen for spring fishing in 2015.

But then they started talking long term.

The friends group is working to raise $150,000 by the fall to pursue their goal of removing the peninsula.

The group also hopes to find a suitable place to move the excavated dirt, especially as it could be costly to simply take it to a landfill. As it turns out, there might be a good alternative 13 miles downriver.

There, the National Park Service has started to rebuild Dyke Marsh, a freshwater wetland south of Alexandria, VA, that, ironically enough, has been eroding for decades since the natural promontory that protected it was dredged for sand and pea gravel in the years leading up to 1970.

Bailey said lining up the sediment needs and timelines of both projects may be a long shot, but an ecological “Hail Mary” worth trying.

“Ultimately, what more efficient way would there be than to move this sediment down the river to Dyke Marsh?” Bailey asked.

Brent Steury, natural resources program manager for the park service’s George Washington Memorial Parkway, is overseeing Dyke Marsh’s restoration. He said the prospect of aligning the two projects “is real,” especially if Fletcher’s Cove can match the timeline of the other work, which is already funded.

“We’d be saving them millions of dollars to use their fill material at Dyke Marsh rather than send it to a landfill,” Steury said. “It saves us money, too, because otherwise we’d have to buy the fill material. So it makes a lot of sense.”

Fletcher’s Cove is one of about nine sites in the region being considered as a potential sediment “donor” for Dyke Marsh, and the project could need to pull from several to amass enough materials. To stay in the running, the sediment must be found free of any heavy metals or other toxic substances that might affect fish or wildlife in the wetland.

The money that the Friends of Fletcher’s Cove is raising this year will go toward testing the sediment.

“Fletcher’s Cove and Fletcher’s Boathouse is really the lifeblood of fishing in the DC metro area,” Noglak said. “People would be beside themselves if they had nowhere to go to have access to our nation’s river.”