One of the best-kept secrets in Washington is the annual run of striped bass up the Potomac. One could almost say a State secret.

In June 1851 the secretary of State, Daniel Webster, received a 10-pound Potomac rockfish as a gift from Charles Lanman, a painter, writer and sportsman.

Webster was so impressed that he asked to join Lanman on a future excursion, and a few days later, arrived at Lanman's house at 4 a.m. in his carriage, ready for the adventure.

Lanman wrote in an article, recently reprinted in the American Flyfisher magazine, that he and Webster were guided that day by one Joe Paine, "the fishing king of the Potomac."

They boarded Paine's rowboat at first light and headed upriver toward Little Falls. "As we struggled to pass over the rushing water," Lanman wrote, "Mr. Webster became excited and actually clapped his hands with glee.

"We fished both with bait and a big yellow fly and it was not long before Mr. Webster hooked a large fish, which was saved with much difficulty, and when in the bottom of the boat the captor uttered a regular yell of delight, and in the excitement nearly lost his rod and reel overboard. The fish weighed 16 pounds."

Lanman wrote that the anglers "continued our sport until near 9 o'clock, when Mr. Webster told Joe Paine, as he handed him $10, that as he was President Fillmore's clerk, it was time for him to return home so that he could be at the department before noon - and thus ended the morning's sport."

Daniel Webster is long gone, leaving behind several sterling legacies. But the rockfish are still going strong.

There's something of a dispute over who the current "fishing king of the Potomac" is, so yesterday all the aspirants gathered at Fletcher's Landing at first light. Joe Fletcher was there, "our No. 1 guide," according to his brother, Ray, who was also on hand.

Billy Collins was there, as were Danny Ward, Dick Tehaan and fly-fisherman Barry Serviente, all bright-eyed in the mist before dawn.

They rowed out across the not-so-rushing water, uttering declarations about the recent spectacular catches Collins, Joe Fletcher and Tehaan had boated better than 60 rockfish one day last week.

They anchored in a line directly out from Fletcher's Landing, a mile south of Chain Bridge.

Collins struck first when a 4 1/2 pound rockfish took his herring head bait. There wasn't enough daylight to snap a picture as he hoisted the striped beast over the gunwale and into the boat.

Collins caught another and then another before Joe Fletcher broke the ice in the next boat in line.

It was an eerie sight, six boats shrouded in mist that was still rising off the slick river. A fisherman sat in the center of each boat, trailing two or three lines off the stern.

They weren't shrouded enough. Some early riser spied the anglers from shore and hallooed across the water.

"Hey, when can I rent a boat?"

"Nine o'clock," Ray Fletcher shouted back.

"Eight o'clock?" asked the voice.

"Nine o'clock," said Ray.

"This is our chance to fish," Joe explained. "All spring, we get here at 5 and 6 o'clock for the perch fishermen and the shad fishermen. When the rockfish come, it's our turn.

"Besides, what good would it do them? They don't have the right bait."

The key to the Fletchers' success with rockfish is fresh-cut herring, which they round up at night. Bloodworms would work, but the little perch and catfish chew them to bits in a hurry.

Few have the Fletchers' patience for collecting the rare remaining herring in the river.

Collins proved to be the fishing king of the Potomac yesterday, boating five nice rockfish before quitting at 9:30. The biggest - the 4 1/2-pounder - didn't come close to matching Daniel Webster's.

But the day before, Collins had hooked into an eight-pounder and he had kept it on ice to prove it.

Tehann, usually one of the top anglers at Fletcher's, had a horrible day. He didn't catch a single rockfish.

Oddly, then, it was Tehaan who suggested a feast back at the dock.

"Hey, let's fry up the catch," he said.

"Fry 'em up?" said Collins. "Why, you don't have anything to fry." CAPTION: Picture, Rockfish anglers sit quietly in the mist as the sun spreads its rays over the Potomac. By Angus Phillips - The Washington Post