The mysteries of the sea run deeper than hook and line will ever descend.

Flounder are in this week at Chincoteaque and Wachapreague on the southern tip of the Eastern Shore. The big flat fish with the tiny bellies are on schedule in their yearly migration from the deep waters of the Continental Shelf to their shallow feeding stations close to shore.

What mysterious clock tells the silent bottom-feeders it is time to move on?

The unschooled flounder will work his way into the sand just off Chincoteaque inlet so that only his eyes protrude. In a matter of minutes his broad brown back will change in color to match the sand above. There he will lurk until the tide sweeps munnow or grass shrimp or tiny crab along, and he will lunge from his hiding place for lunch.

The eyes themselves are a mystery. Flounder are hatched with conventional head structure, an eye on either side. But in the transformation from larva to flat fish one eye rolls across the great divide and joins the other on the fish's back.

And if you should dance a hooked minnow past an unwitting flounder and he takes it, once you get him in the boat he will regurgitate all the undigested food he's taken in an effort to disgorge the offending particle.

We watched this little spectacle 60 times last weekend on a delightful outing with Captain Jim Lewis aboard his fast ocean-going skiff, the Sandy B.

Lewis decided 10 years ago that the mysteries of Chincoteaque were the ones he'd like best to wrestle with. He'd finished the waters of the Chesapeake Bay and the streams and ponds around his Silver Spring home. But one trip to Chincoteaqu sold him.

"I'm an organizer," said Lewis, 43, an insurance investigator on his working days. "That's what I do best."

So he set to work organizing a way to pursue his avocation and make it pay. It took eight years before it all came together in a low-key, fish-with-your-friends charter boat operation. And now it's just the way Lewis wants it.

"If I was a millionaire I wouldn't change a thing," he said, gesturing broadly at the stilt house he owns at water's edge and the skiff bumping gently at his dock.

Indeed, Lewis' package is neatly tied. He uses the best gear: Fenwick rods for him and his customers, well-oiled Penn reels. The house is open to charterers at $8 a room per night and fishing voyages usually end in feasts at the Lewis family table with Lewis doing the cooking.

And the skipper can put you on the fish. The 23-foot Fortune has as deep-vee a hull as you can get, which suits it to the rolling open ocean as well as the calm bays around the little island.

Our fortunes were in doubt only briefly Friday. Wind is never a good sign for anglers, and the rainy northwester that was piping up at 25 knots when we went to sleep was followed by clear skies but no wind abatement in the morning.

We bided time, stuffing ourselves at Bill's Restaurant in rustic downtown. At 10:30 with the wind still howling, we went to sea. Lewis' 12-year-old, Jimmy, manned the tackle as mate.

The going was rough, but within an hour we had hit our first pocket of flounder along a sandy tidal bar. The fish struck slowly, gently mouthing the minnows we had on spinner hooks before they took the bait.

These were no little fish. They came up like ash can covers, with at least a couple weighing four pounds.

Lewis moved us around, setting up at the head of tidal runs and drifting back across dropoffs to the channel. We had our best luck jsut where the bottom fell off, usually from six feet to bout 10. Three ounces of lead held the bait to the bottom.

Lewis picks his spots from an aerial photo of the island by the U.S. Geological Survey. The picture shows where fast-running water crosses the bars, and that's where the flounder were.

By dusk we had loaded the cooler and the wind finally had died. While Quay Jones, a Silver Spring neighbor, and little Jimmy and I fileted the big fish back at the cottage, Lewis manned the galley. By 9:30 we were gorging ourselves again, this time on the freshest of fresh fish.

Flounder make the first run in scenic Chincoteaque, but later in the summer Lewis and the other skippers will be pursuing blues, tuna, king mackerel, croaker, trout, marlin dolphin, drum and wahoo.

There is one sad note for anglers intrigued with the little seaside town. Lewis said the two headboats that have traditionally worked there have been retired in favor of clam dredgers that are working quadrants of the open ocean en masse.

But there's good news there, too. The clam dredgers stir up the bottom and make for great fishing for charter skippers who trail behind.

And there's no mystery to that.