Sometimes it seems we march to a metronome. Time to get up, time to eat, time to work, time to do our taxes.

Last weekend a friend who works all week took his fishing rod and a box of worms down to the Potomac. Rain had raised the river and made it fast and dark, and the warm spring day held a hint of evening thunderstorms.

On the bank near Swains Lock, he plunked his worm in the fast water and waited as it washed downstream. He retrieved it and tossed it out again. He could feel the small lead sinker and the line working over the rocks. He learned the river bottom. He sprayed his casts to cover a wide area of riffles, pools and deep, fast channels.

After many tries, there came an unnatural bump on the line. The fisherman lifted the rod tip and jerked it. The tip jerked back at him, and he felt the staccato rhythms of life at the other end. It was a smallmouth bass, about 12 inches long. He took out the hook and dropped the fish back in the river. "A lot of times I keep 'em to eat," he said, "but this one was a little small for me."

The next day he was back on the bank again, this time above Great Falls.He caught two smallmouths, fishing the same way, and returned them to the river.

On Monday he was back at work.

If that sounds like idle pleasure, so be it. Fishing is one of America's favorite recreations for good reason. It involves a suspension of time and reason, an acceptance of the life cycles of beasts utterly different from us.

An escape.

Washington is a fisherman's paradise. The Potomac offers largemouth bass, smallmouth bass, stripped bass, crappies, bluegills, catfish, spawning perch and shad.

"That's what we dream about," an old angler said the other day as his cork bobbed under the water in the Tidal Basin. "To see that cork go under. You don't know what it is and you don't care. You just know it's a fish and you've got him on your line."

The Potomac is alive and well, and within a two-hour drive lie an endless succession of angling opportunities, in lakes and ponds and streams, including some of the most challenging trout waters in the nation; and, of course, the Chesapeake Bay, the world's largest estuary, which has flounders, stripers and so many bluefish "you don't dare put your hand in the water," a marine biologist once said.

It's all there and it's always different. Every time.

So let's go freshwater fishing, PAGE 44; or fly fishing, PAGE 45; or saltwater fishing, PAGE 46. Or all three. CAPTION: Illustration, No Caption