When Capt. John MacEwen quit the fishing grounds near James Island in the dead of night last week and struck a course for home across Chesapeake Bay, he didn't have a star by which to steer the Tom Hooker. He had a whole constellation.

And not just any constellation, but the most recognizable one in the Northern Hemisphere--the Big Dipper, which hung as prettily on the northwest horizon as it has anywhere.

With a waning half-moon yet to rise, there was nothing in the night sky to dim the Dipper save for the distant, fuzzy arc of man-made light from Annapolis and Baltimore and the odd set of running lights from small boats skipping along the waves on a mild summer's night.

It's an hour's run back from James Island at the mouth of the Choptank River to Chesapeake Beach on the western shore. We were due at the dock at midnight and MacEwen, who has run charter boats for 25 years, missed the mark by only a minute.

"Twelve-oh-one, honey," John Nagle of Kensington said to his fiancee, Amy Elieff, tapping his watch as the mates made fast the inch-thick dock-lines of the 65-footer. "Isn't that something?"

The elderly gentleman next to him groaned contentedly as he hoisted a cooler full of croakers, sea trout, rockfish and spots he had caught during the previous six hours and confided to me: "I ain't cleaning these fish tonight. They're going to have to wait till tomorrow. I've got plenty of ice in the box. They'll keep. I'm going home and go to bed."

So it goes on the night shift. With croaker fishing booming on the bay this year, the Hooker has added an extra captain and crew to run night trips out of Chesapeake Beach seven days a week, in addition to regular day trips across the bay to bottom-fish the shoals at the mouth of the Choptank.

Capt. Tommy Rials, who has run the Tom Hooker for years, even went to New Jersey and bought a second boat to handle the double duty. These days, he runs the newer Lady Hooker in the daytime and has hired a second crew to run the Tom Hooker at night.

Days are mostly for spots, small but delectable bottom feeders, that have arrived in abundance with the warm weather, as they do most years. Nights are mostly for larger croakers, or hardheads as they are widely known in bay country.

"The bigger hardheads seem to bite best after dark," MacEwen said as he piloted the Tom Hooker to the fishing grounds. He'd cast off the lines at 6 p.m. and pointed the bow southeast toward the low-lying marsh islands of the Eastern Shore. "But some nights are better than others."

At 7 p.m., the anchor was down and 49 eager anglers, a big crowd for midweek, sent baits plunging to the bottom in 25 feet of water. Bait came in variety. Jerry Williams of Baltimore, perched next to me on the port side, had razor clams and squid. I had bloodworms and shrimp. All four wound up producing fish, though bloodworms seemed to bring the most bites.

The big winners were John Kenny and John Hammond from Hyattsville, brothers-in-law who set up in the bow with a few plump soft crabs. The croakers could not resist chunks of soft crab, nor could anything else. Kenny won the big-fish pool with a four-pound rockfish caught on a soft crab bait.

But we're getting ahead of the story. First there was a two-hour wait. "It doesn't usually get good till the sun goes down," said mate Brad Buck, who roamed the deck waiting for something to happen as evening light gave way to dusk. We picked along, catching mostly spots for the first hour or two, but they were few and far between.

As night came creeping across the water, MacEwen first flipped on the cabin lights so we could see what we were doing on deck, then ignited a set of big mercury vapor lights that ringed the cabintop, and shone brilliantly on the water.

It took an hour or so before the bright lights began to have the desired effect. Steadily, crowds of critters filtered in to browse in the fake daylight. Minnows skittered across the surface, a spear-nosed gar cruised in and here came the crabs--females with their fingernails painted orange, big males with their blue swim fins paddling madly.

Back and forth the crabs skittered, gobbling whatever they could find to eat. They got so plentiful they'd bump against your fishing line, then cling to it briefly to see if it was edible.

Meantime, fishing was getting hot. Willie Moore from Fort Washington set the hook on a jumbo croaker that bent his pole nearly double. Next to him, Jim Dorsey of Laurel cranked in a doubleheader of fat Norfolk spots. Kenny and Hammond in the bow yanked fish in one after another on soft crab, while Nagle and Elieff, relatively new to the sport, struggled to keep their lines untangled as they simultaneously fought fish.

"It's always like this--the tide starts running and the fish start biting," said one of the mates, who stopped by to sort out a line tangle. Indeed, the flow of water beneath was visibly picking up--the crabs shining in the mercury vapor lights now swept north at a pretty good clip. I found if I casted out 30 or 40 feet, my bait would settle to the bottom right at the outer edge of the arc of the light where the most bites seemed to come. The croakers were huge, up to 17 and 18 inches.

All around came shouts and hollers--cries for the mate to bring the net for a keeper rockfish or trout, confusion as lines tangled and excitement as another fat croaker came aboard. Too soon the little hand hit 11 and the big hand hit 12 and it was time to head for home.

I wandered up to the bow, out of the glare of the cabin lights, and stared over the bowsprit at the Big Dipper pointing the way back. It had been a very pleasant night, and productive.

The Tom Hooker runs bottom fishing trips at 6 p.m. daily out of the Rod 'n' Reel Dock, no reservations needed; the fee of $32 includes a bag of bloodworms for bait. Rental rods and reels available. Fee is the same for day trips on the Lady Hooker, which leaves at 8 a.m. Weekend trips often fill up, so it's a good idea to arrive early on weekends. For information, call 1-800-233-2080.