Jerry Ostheimer, associate director of obstetrical anesthesia at Boston's Brigham and Women's Hospital, wears a digital watch with a host of buzzers and chimes, befitting a man of science.

He was driving down a snowy back road before dawn last week on his way to a day of lectures and conferences in New York. From his wrist came a computerized "MEEP MEEP; MEEP MEEP." Ostheimer smiled.

Obstetrical emergency?

"Nope," said Ostheimer. "Legal shooting time. It's always hectic in the marsh before dawn. You're setting out decoys, slipping around in the mud and the ducks are flying. When we're setting up and somebody asks me if it's shooting time (a half-hour before sunup) I know the answer, because I set the alarm the night before." The watch stays set on that crucial hour whether he's hunting or lecturing.

That's about the only intrusion of a methodical mind on Ostheimer's hunting style. He lends new credence to the theory that a successful duck hunt is one in which the same number of hunters come home as went out.

"It's going to be all or nothing this morning," Ostheimer said as we stepped out into the darkness of the Weweantic River last week, burdened with bags of decoys, shotguns, portable blinds, chest-high waders and an overenthusiastic Labrador retriever.

A freak early snowstorm had decked the ground in white. Behind the clouds the moon was nearly full, creating one of the highest tides of the year, a spring tide in winter. "Black ducks feed in the marsh on this kind of tide," said Ostheimer, the thought of which had lured me 500 miles to try New England ducking. But Ostheimer worried that the storm might have pushed the ducks south already.

The river water was knee-high in the marsh and new snow was riding horizontally on the wings of a northeaster. "Follow me," said the doc, a huge, bearded fellow, and set off with a load, breaking skim ice with size 14 boots.

One of the scarier things in life is to walk into a mysterious Massachusetts river at night in a December snowstorm. A hundred yards out Ostheimer stopped, scattered some decoys, set up the homemade blind, pointed at places one shouldn't step at risk of mortality and lumbered off to a spot of his own, out of sight.

From across the marsh came an eerie sound.

"MEEP MEEP; MEEP MEEP."

Ostheimer was right about the ducks fleeing the onslaught of snow, and although we saw a couple of large flocks flitting around the mouth of the river a half-mile away, nothing much was moving on the marsh. We watched the tide roar out of the cuts and sloughs, took a couple of fruitless long shots at speeding ducks and soon Ostheimer was back at our starting spot, heaving and panting.

"I fell in," he said. "Let's head back to the house and warm up."

In most places the disappearance of the marsh ducks would herald the end of a miscast day and the close of the season, but New England hard-core hunters have a last refuge.

"Dippers," said Ostheimer. "We can go down to Will Cochran's mother's place and try for some dippers." Dippers is New England parlance for buffleheads, small, jet-fast ducks that favor saltier water and stay late in the winter.

We drove 50 miles out on Cape Cod where the snowy wind was howling even louder. The dippers were racing from islands to shore to open water at just under the speed of light.

Scallop boats dotted Pleasant Bay as winter watermen scraped the shallows from small skiffs. Whenever the scallopers moved their boats they set another flock of dippers in motion.

Buffleheads are interesting. For reasons known only to them, they will do almost anything to avoid flying over land. Ostheimer said that by rowing over to nearby Sipson Island we could walk out on a sandspit and wait for the dippers to fly between the island and the mainland. In the evening, he said, the action was wild.

The doc spoke the truth. A half-hour before dusk, buffleheads began swooping through the cut like dive bombers and our shotguns went off in chorus. Beautiful birds, these. They fly so fast that often they simply appear in front of you in the gray dusk and are gone before you raise the gun. Or you hear them, the flutter of wind like a fan, then a splash of black and white in frantic motion. Gone.

We took eight buffleheads and an errant brant before dark closed in. Then Ostheimer clambered aboard an eight-foot plywood pram with the ducks and the dog and a pile of gear in the bow, and rowed across the stormy channel with at least six inches of freeboard.

Another successful hunt. Everybody who went came back.