The wind is down and the water smooth and fast at 5:45 each morning when Kathy Patterson arrives at the Potomac Boat Club in Georgetown. With most of the city still asleep, there's a feeling of serenity and purpose that rowers claim is theirs alone. Gingerly, she lifts her single-seat shell above her head and navigates the cramped runway onto the portable dock.

The only other activity is that of her fellow PBC members, the only sounds their banter, good-natured but brief. Doctors, lawyers, students, people from all walks of life, they share the classless society of the boathouse in Georgetown and its unspoken rewards.

"Everyone thinks you're so great because you get up for practice at 5 a.m., but actually I believe that it's easier to get motivated knowing that there are other people waiting on the docks for you," says Patterson, office manager for the Oliver T. Carr Co. "In fact, one reason I enjoy rowing is because of its early-morning practice time."

Patterson began rowing as a junior at George Washington University, but she became a serious, top-flight rower after college. From 1980 until 1982, she and Julie Shaffer, a former PBC member, were the national lightweight doubles champions.

Gently placing the shell in the water, Patterson climbs in and grabs the oars. Unlike crew, in which a rower pulls just one oar, she must negotiate two and steer the shell without the aid or encouragement of a coxswain.

The training ritual begins about a hundred yards upriver at Three Sisters Island, where she changes direction and heads south past Key Bridge and the Kennedy Center to the 14th Street Bridge or National Airport, depending on her practice schedule. Scarcely resting, Patterson turns around and heads back to the PBC. A simple regimen, but difficult for anyone not in top condition. A quick shower and she's on her way to work by 8.

She likes solo sculling for recreation, but other rowers find the individual competition especially challenging.

"You don't have to depend on anyone else. It's just you against the other guy," says Joe Paduda, a graduate student at American University. "It's real obvious when you get tired. The boat just stops in the water."

As exhausting as the sport is, neither Patterson nor Paduda could give it up after college, so they joined the Potomac Boat Club, an honored if unkempt refuge for rowing addicts next to Key Bridge on Water Street.

The club is the only outfit in the area with a bit of something for everyone. For a novice, it offers just about the only place outside a few high schools and universities where you can get basic instruction plus use of a costly shell without buying your own. (Small-group or individual sculling lessons for beginners are also available at the Occoquan Boat Club, near Lorton.)

For veterans, the Potomac Boat Club offers competition and camaraderie.

Only 80 of the club's 220 members are active competitive or recreational oarsmen. The rest, who may row only once a week or less, still stop by the second-floor outdoor porch overlooking the river just to drink a few beers and talk rowing on an afternoon.

Since rowers compete more against themselves than anyone else, there's a free exchange of strategy, technique and experi ence.

"Everyone is very helpful," Paduda says. "I row several times a week against other members just to see how I'm progressing. There's always someone around to lend a hand."

It costs $20 to join the club and quarterly fees are $36; membership is full. There's usually about a six-month wait for admission. Unlike some other prestigious East Coast clubs, the PBC has admitted women for several years and several are active in the club's leadership.

Buying a shell can be expensive -- a used single training shell is at least $700, while a new racing shell can cost several times that much. New rowers are encouraged to use borrowed or club equipment until sure of their commitment to a sport that Paduda describes this way:

"You must physically beat yourself into the ground and then make correct split- second strategic decisions while suffering oxygen debt. It's a masochistic sport, but I love it."

"I just can't seem to give it up," he says. "I . . . always seem to come back."