Carlton "Cork" Mcgee stood knee-deep in the marsh off Chincoteague Island, wondering once again whether he would ever come to understand the wild and beautiful Virginia coast from which he makes his living.

"Cap'n," he said to the gunner he was guiding, "it made such a tide Saturday that I got a limit of marsh hens just wading along here with my seven-year-old grandson. It made such a tide yesterday that it covered my dock. You saw how the tide made when you came in last night, and with that northeast wind still blowing steady it should be making such a tide now."

Mcgee tasted the wind again and considered the set of the current through the channel where he had drawn up his boat. "I would have bet on it, but I don't believe this tide is going to make up enough for us to pull the boat. If you want some marsh hens, we'll have to walk them up."

The client was more than willing, because it was a rare day for September on the Eastern Shore: not cold and not hot and not a mosquito or greenhead fly to be seen, three days of onshore wind having blown them all inland to bedevil the dove hunters.

It is also a rare season for marsh hens-the several species of tasty rails that are the most common and least-seen birds of the coastal zone. This spring, for the first time in several years, there were no storms or flood tides during their nesting season, and since high summer the cackling of the rails, which suggests the raving of demented chickens, has been the dominant night sound of the marsh.

"Even in a bad year there is a lot of them," Randy Lewis of Wachapreague had said. Lewis, another of the few shoremen who are willing to guide rail hunters, said, "The problem is to find them, because they're so skinny they just slip through the grass ahead of you, or hunker down and wait for you to pass. For every one that flushes there must be a hundred hiding. You need an extra high tide to make it worth going after them because that concentrates them on the high ground."

Lacking such a tide, as happened this day, the solution is to have the eyes of Cork Mcgee. After a few minutes of sloshing through the grass, he stopped and pointed. "Look there," he said. "How is a man supposed to find something like that?"

His client peered along the line of Mcgee's finger. Grasshoppers he saw, and periwinkles, and funny-looking bugs, and a baby blue crab and several clam shells. No rail bird did he see. "There," Mcgee said, and the gunner bent low. There were worm burrows, yes, and dead stalks of grass whose detritus is the basic fuel that powers the chain of life in the marsh. A tiny mullet zipped by, foraging in the few inches of water and safe for the moment from big fish. But if there was a long brown bird there, the gunner couldn't see it.

Mcgee reached past his client's nose and picked up the Virginia rail that had been crouched under the client's eyes, leaving the client to wonder how Mcgee had produced the bird from his sleeve when all he was wearing was a T-shirt.

"You have to know what to look for," Mcgee said, "but don't ask me what that is because I couldn't tell you. There are plenty of others all around us, but we'll never see them."

"I don't believe I saw that," the gunner said. "You can't go out hunting and just pick up birds in your hand."

"You'll do it too, if you walk the marsh long enough, "Mcgee said.

"Walk is not quite the word for making one's way through the marsh. "Slog" is more like it, except when there comes a soft spot which calls for floudering, or a channel which may require a swim. The uniform is old clothes and tennis shoes.

The effort is rewarded with the beginnings of an understanding of how rich with life is the apparently empty expanse. The marsh fairly boils with swimming, scuttling, creeping, crawling and flying creatures. And virtually all the salt marsh of the Delmarva Peninsula is open to anyone who has a rowboat or canoe to get to them. In many cases one can walk in from a road.

The idea is to stride along faster than the rails can slip through the grass, so that they flush. If one works along toward a point or a narrow place, some reluctant flyers may take wing rather than venture into the open. Rails don't like to fly because they don't do it very well and make easy targets, although Mcgee and his client were managing to miss fairly consistently.

Time and again Mcgee pointed out a crouching bird, and after several hours of schooling the client finally learned what to look for well enough that he spotted a bird on his own. He stood over it, curiously reluctant to touch it. When he did close his hand around the bird the sense of quivering life was electric.

The hunters worked several "islands," or patches of marsh separated by creeks and channels. It added up to several miles of marching and they still were short of the bag limit of 15 each, but the tide was falling and the client's legs were failing. "I can still put my feet down pretty well," he confessed to Mcgee, "but I can't pick them up anymore."