Hundreds of buoys mark the shipping channel of the Chesapeake Bay, and Capt. Elizabeth Christman is not boasting when she says she has memorized them all--how they sound, whether they have bells, how often they flash, their location. She knows them all because she must, as she precisely steers a 425-foot Dutch cargo ship down narrow channels and shifting shoals on a dark, rainy night on the bay.

As the ship passed a flashing green light in the watery dark, Christman said mechanically: "That's buoy No. 83. Green light, every four seconds."

Christman is navigating charted waters, but she is only the second woman to do so in the 147-year history of the Association of Maryland Pilots, a small group of specially trained and licensed maritime professionals who guide oceangoing ships up and down the bay, from sea to port and back, keeping them from running aground.

It is an elite profession historically dominated by men. In the United States there are just 1,100 licensed pilots, and only 13 are women--most installed in their jobs in recent years.

Recently, the Greek captain of a cargo ship full of sugar bound for Baltimore exclaimed in surprise as Christman prepared to steer his ship, "I've been a captain for 50 years, and I've never seen a woman pilot."

Christman's response was quick and confident. "Well, captain, this is your lucky day." And she went on to guide the ship safely through 150 miles of the Chesapeake Bay, one of the longest and most difficult piloted runs in the country.

Christman is loath to dwell on the subject of her status as a woman in a man's world.

"I drive ships," she said simply, as she stood inside the bridge of the Alblasgracht, in front of a radar screen pulsing yellow outlines of the bay shore. "I pilot up and down the Chesapeake Bay.

"I'm not very comfortable with the woman thing," Christman said in the precise, direct language she speaks at sea. "I'm not some flag bearer. I got this job because I worked very hard to get here."

She is, by appearance and command, all business. From her sturdy brown shoes to her tailored burgundy jacket and simple blue-striped shirt, she is all order. Her wavy, brown hair is drawn from her face with a thin leather headband, in a style that would fit at a country club luncheon.

"We'll have two floods plus an ebb and a half," Christman said, explaining the bay's tides to Capt. Marcell Buurs of the Alblasgracht before setting out from Baltimore in the late afternoon. "But the wind is gonna be against us."

Christman, 34, who lives on the waterfront at Fells Point in Baltimore, started her maritime career at the State University of New York Maritime College in the Bronx. Her initial goal was to become an admiralty lawyer.

On the college's training ships, she accumulated practical experience at sea. She graduated at 22 with a degree in marine transportation, a third mate's license and a commission in the Naval Reserve. Then she worked general purpose maintenance on a tanker, a job that "means close to being a slave," she said. After that, Christman was a deckhand on New York tugboats.

She entered the graduate program at SUNY Maritime and went off to sea for four more years, all the while working her way up the ranks. In 1992, she received her unlimited master license and the title of captain.

"In high school, I knew I didn't want a desk job," said Christman, who grew up in Norwich, N.Y., the second daughter of a car salesman. She has little explanation for her lifelong interest in water and the sea but offers her memory of the first time she saw the ocean, at Rehoboth Beach, Del., when she was 5 years old.

"I don't know. I was born in February, and I'm an Aquarius. That's not a real answer," she said.

The door to the world of Chesapeake Bay piloting was opened in 1992 by Capt. Allison Ross, the Maryland association's first female pilot--first on the East Coast and the second in the nation.

Senior pilots knew they were making history when they brought Ross into the association. But it was also a time when the pilots' ranks were expanding so the veterans were also adjusting to other young trainees, the first in 10 years.

Before 1992, no female pilot had been in the pilothouse at Cape Henry, Va. The association had to install women's quarters and bathrooms.

Early last year, Christman finished a two-year internship and became a junior pilot.

"She came in here, and nobody blinked," said Ross, 37, who is now a senior pilot. "I see how they [men pilots] treat her, and the fact they don't even notice she's a woman, that nobody creates an issue . . . makes me think that I've done something right," Ross said.

Christman is, in her words, "just one of the guys." In this work circle, at sea or on the docks, there are men with bulging, tattooed arms who address each other by last names. But the honorific applies for Christman: It's Capt. Beth. Other ship captains have addressed her "Lady Pilot." Years ago, street vendors in the Kenyan port of Mombasa who learned that she was third mate on a docked ship called her "Boss Lady."

Piloting is the choicest of maritime jobs because it allows people who love the sea to continue to work on ships, but the short trips mean they can have a family life, too, said Jack Sparks, president of the American Pilots' Association, a national trade group.

Openings are rare in the occupation. The Association of Maryland Pilots does not expect to take on apprentices again for at least five years.

The few maritime schools in the country didn't open their doors to women until the mid-1970s, so the pool of potential women pilots has been limited, Sparks said.

But slowly, the industry is changing and recruiting women and minorities, he said.

The Association of Maryland Pilots, founded in 1852, is the first and oldest portwide organization in the country. But piloting in Maryland had its roots in St. Mary's County and Southern Maryland, where the first seaports were, according to Bryan Hope, a senior pilot and the association's in-house historian.

In the old days, pilot schooners would race to the tall ships coming into port, with the first to reach them winning their business. The state began regulating the industry in 1853, mostly to ensure that ships unfamiliar with inland waters would make port safely with the help of pilots who knew the waters.

Today the association comprises 60 senior pilots and six junior pilots. It operates like a private partnership but is regulated by the state. The senior pilots, like partners in a law firm, have a full interest in the business, and the junior pilots have a lesser share.

Christman has more than a year of junior status left before she can become a senior pilot. On the drive from her office to Baltimore municipal piers recently, she pointed to the ships at dock.

"I've piloted that one, that one, that one," she said.

She has steered 235 ships on the bay since becoming a junior pilot--tall ships, cruise ships, ships that repair trans-Atlantic cables and cargo ships full of sugar, iron ore, aluminum, wood pulp and cars. Her first was a tugboat called "Two Bouchard Girls," with barges in tow to Piney Point in St. Mary's County.

"This is it for me," she says, certain of the water's lure for her even if she doesn't have a real answer why.

CAPTION: Christman, center, practices rescue techniques with pilot Ron Steele, left, and launchman Richard Peck. The three are wearing survival suits.

CAPTION: Christman studies a Chesapeake Bay chart and the currents to be encountered before beginning a trip.

CAPTION: Capt. Elizabeth Christman organizes her ship's log in her home, in the Fells Point section of Baltimore, before leaving for work. Christman keeps detailed statistics on each of the ships she pilots.

CAPTION: Christman's Route (This graphic was not available)