Clarence and Danny had already fished near the docks on Smoot Bay. They had taken their boat out to the rusted tug hulk in mid-river. They had tried Rich Man’s Cove, on the Virginia shore.

Clarence Eggleston, 10, a fifth-grader at Southwest’s Amidon-Bowen Elementary School, and Danny Moffat, 54, a retired UPS driver from St. Charles, were out on the Potomac on Friday in search of largemouth bass.

Clarence had never been fishing before. Moffat was a volunteer angling veteran with a bass boat full of rods, a head full of lore and a feel for finding fish. And as part of an outdoors program for youngsters, they were fishing buddies for the morning.

Now they were headed back to Smoot Bay, where they had bagged fish earlier but then violated a prime rule of angling: “Never leave fish to catch fish.”

For three hours Friday, the pint-size youngster and the seasoned veteran stalked the river with plastic worms, a spray can of crawfish-scented fish attractant and an array of electronic gear that scanned beneath the surface.

In the end, four fat bass were hooked by Moffat, who let Clarence reel them in. And Clarence caught one by himself.

He pronounced things “awesome” and immediately said he wanted to quit school and start his own fishing tournament.

Their trip was part of a program hosted by the nonprofit Living Classrooms, Pepco, the U.S. Fish and Wildlife Service, and FLW Outdoors, which is running a huge professional bass fishing tournament on the Potomac this weekend at National Harbor.

The idea was to get city and suburban children outdoors, expose them to the thrill (and, sometimes, the tedium) of fishing, and put them on one of the nation’s most hallowed rivers on an exquisite spring morning.

“Kids don’t really understand their outdoors very well,” said Rowan Gould, deputy director of the Fish and Wildlife Service. They’re “just not understanding the environment.”

He said outings like this can change that.

The fishing duo, accompanied by Gould, set out from the harbor at 7:30 a.m. aboard Moffat’s boat. On other boats were more than a dozen other youngsters, all vying to see who could bring back the biggest fish.

The tournament pros, faces sunburned except for the imprint of their sunglasses, had departed an hour earlier.

Dressed in camouflage, they looked like commandos. Their bundles of fishing rods were sheathed to keep their rigging secret from competitors. And they drove fast, state-of-the-art boats emblazoned with sponsors’ names and capable of doing 70 mph.

A wiley bass hunter himself, Moffat knew the spots on the river where largemouths lurked.

And his boat, pushed by its 250-horsepower engine, rocketed across the water so fast that he and Clarence donned hockey-like face masks for protection against the wind.

Moffat began by showing Clarence a basic one, two, three method of casting with a rod and spinning reel.

One, hold the rod so the bait hangs at eye level. Two, flip open the bail on the reel to allow the line to play out. Three, cast.

Clarence, who wore blue jeans, black sneakers and a yellow life vest, caught on quickly. For bait, they used red-wine-colored plastic worms with wiggly tails.

Moffat had said earlier that his goal was for Clarence to catch his first fish. “When I see his face light up, that makes my day,” he said. “Until he catches that first fish, I’m going to be tense.”

The fishing was a little slow, although Moffat hooked three bass. As they fished, he probed the bottom for “structure” and holes that might hold fish.

After a few minutes at Rich Man’s Cove, Moffat said he could “feel” there were no fish present. They streaked back to Smoot Bay.

“I know there’s a fish there,” he told Clarence as the boat floated quietly beside a dock. “You almost got to feel it. You can’t go out there thinking you’re not going to catch fish. You might as well go back to the ranch.”

Suddenly, Clarence’s rod bent and began to dance. He had hooked his bass. Moffat helped him maneuver the fish to the side of the boat and hauled it in with a net.

“We can go eat now,” a delighted Moffat said.

Clarence put on a glove, grabbed the fish by its lower jaw, as Moffat had showed him, and held it up. Their catch would place third, but that seemed beside the point.

“I told you he was here!” Moffat said. “I knew he was here!”