A sea trout bonanza is under way in the mouth of the Choptank River, but that's no secret. Half the Chesapeake Bay seems to know about it.

They were there -- big boats, little boats, tin rowboats with outboards, tri-hulls, deep vees, Bay-builts, even a sailboat -- drifting lazily on a Monday morning last week. At 7 a.m.

It looked like Resurrection City on the high seas.

"They're on one school of fish," said Dick Houghland, captain of the charter boat Mary Lou. "I know of three other schools out here. I don't care to fight with those guys all morning. Let's see if we can find another bunch of fish."

He didn't go far. The big clutch of boats was about a mile due east of Sharps Island Light, the most easily distinguishable navigational marker on the bay. Some years back winter ice pushed the big lighthouse over at an angle and there it sits.

Mary Lou began the sea trout search about a mile north of the cockeyed lighthouse. Houghland watched the sparks on the depth finder as he idled along. The bottom was 20 feet down and frequently the machine would show great swatches of fish at varying depths. Houghland laughed them off.

"Just bait," he said. "Garbage fish."

So how could he tell the real thing?

"You'll see," he said. "The whole bottom will rise up into a big hill. These fish hold right down on the bottom and they'll pile up in hills, sometimes four and five feet high."

The four anglers aboard gathered around the captain's chair and oohed and aahed each time the machine lit up, and each time Houghland chuckled that it was more "garbage."

Finding fish takes time. The anglers soon tired of the concentration of the effort. They were reclining in the stern when Houghland leaped from the chair, tossed out a marker buoy and stopped the boat.

"Good Lord what a pile of fish!" he exclaimed. "Get those bucktails in the water."

The fishermen jumped to, and as the Mary Lou drifted with the tide across the acre of fish, they cast and slowly retrieved half ounce hair lures with pork rinds on the hook.

On the first drift two sea trout took the baits and were boated, and several others tugged but didn't take. On the second drift there were fewer bites and no fish, and again on the third. The great pile of trout was dispersing.

It took Houghland another half-hour to rediscover the school, and when he did he looked up and saw trouble coming.

"Nothing but bows" he said, his finger pointing to the armada from down south descending on the Mary Lou bows-first. "Get 'em quick," said Houghland, "because it's gonna be a zoo."

It was. Before the first drift was done he was surrounded by boats from Tilghman Island, Baltimore.Annapolis, Grasonville, North Beach; boats with long names, with short names and boats with no names at all.

With consummate good humor and boat-handling skill Houghland managed to hold Mary Lou in the middle of this mad pack and put his anglers consistently over the school, which was moving north to escape the chaos.

Time after time he pulled back the throttles just a few feet from some menacing newcomer, directed the casts and watched the anglers hoist up beautiful golden sea trout (called goldfish by the locals). .the fish weighed three to nine pounds, mostly on the larger end.

It went on like that until noon, when the traffic jam grew unbearable.

The captain set a course for James Island 10 miles south at the mouth of the Little Choptank, where the remaining two schools were thought to be.

There, in less crowded waters, the day drew to an incredibly successful close

Five boats hovered around a marker buoy off James Island, and when Mary Lou passed by Houghland whistled. 'I don't know who threw that marker but he put it right on a big pile of fish."

From interloped upon he became the interloper, joining the little clutch of boats. The fishing was superb, though the trout were slightly smaller. By 5 p.m. the catch-box was full and the four anglers took to releasing the fish once they had brought them to the boat.

They made their way home into a blood red sunset with 60 trout, seven bluefish and a flounder in the box, and plenty of others left to catch again.

"It's amazing," said Houghland, who fishes these waters six days a week. "You can come out here and terrorize these fish all day alongside 30 other boats. Come back the next day and the same school is there and it looks just as big."

The sea trout explosion at the mouth of the Choptank was first noticed four years ago. No one knows whether the fish were there in the falls of years before that or not. Fishermen were too busy catching striped bass in the good old days before the stripers grew scarce.

Now the fleet is onto the sea trout blitz for its fourth straight fall and the parameters of the season are beginning to take shape.

Sharps Island trout were first caught this year around the third week of August. The big fish spend most of the summer further south in the Bay. They appear to be chasing bait when they move up into the midbay area.

The good news is that they're here for awhile. Excellent fishing should continue through the middle of October if past history holds.