It was past supper-time when I checked into the General Mitchell Motel in Hatteras, N.C., after the seven-hour drive from Maryland last week. But before heading to the Channel Bass Inn, where Lady Bird Johnson once enjoyed a fish dinner, I wanted to dip a toe in the sea.

From the dunes behind the motel, the sand stretched to a hazy horizon, surf rumbled and roared, gulls and terns wheeled and dove and two or three surf fishermen stood lonely vigil over their poles. "Poor devils," I muttered, "they never catch anything."

On cue came the distinctive shriek of line tugged off a reel. The surf-rodder nearest, just 100 yards down the beach, dashed for the rod, which was bent and bowed in a plastic sand-spike holder.

He yanked it out and began pumping and reeling to get control of the fish. It was a big one. Line stripped off in bursts and the rod tip shook.

The scene was unusual in two ways. For one, the rod was not a surf-casting rig at all but a trolling refugee from some offshore boat with a long, burnished steel handle designed for a transom rod-holder and a conventional reel big enough to use to fight marlin in the Gulf Stream.

And when the fading sun glinted off it, you could see the line stretched far into the sea, a couple hundred yards, anyway, well beyond range for even a proper casting rod, which this wasn't.

I slid over to watch. The man fought the fish standing up for a while, but the rod handle dug in so hard he jammed it back in the sand spike and got on his knees to reel. The fish put up a good fight.

"Shark?" I asked.

"Oh, no," said the fisherman. "It's a cobia. That's what I'm fishing for."

Soon the great dusky fish was thrashing in the shallows near shore. It did look like a cobia. The angler pulled the rod from the holder and backed up the beach until he hit the dune line, the fish still thrashing in the suds. He beckoned to me urgently.

"Could you keep the line tight while I go down and grab that fish?"

I took the heavy rod and kept the slack out while he scampered into ankle-deep water and manhandled the big fish, which squirmed away twice before he had it safely up on dry sand, still flailing. A crowd gathered to admire the meaty 30-pounder.

"I've been doing this 18 years," said Rick Hodges, of Knotts Island, N.C., "and that's the first time I ever caught anything like this."

I was still puzzling over how he did it. "Simple," said Hodges, a ceramic tile installer on vacation with his wife, Wendy, and kids. "See that kayak?" He pointed to a brightly colored surf toy parked in the sand.

"My wife caught a live spot in the surf and gave it to me for bait, and I paddled it out about 300 yards in the kayak and dropped it over. I clipped it to a weight with a snap that releases when the fish picks it up, so I didn't have to fight the weight back in. It was just me against the fish."

The boat rod, he said, was one he kept when he sold his 23-foot Sea Ox several years ago. "We used to go trolling in the Gulf Stream, but now I just fish the beach. Everybody wants to catch a big one from shore," added Hodges, "but it took a dumb construction worker to show them how."

In fact, Hodges isn't the first surf fisherman to use a little boat to get his bait out to big fish, but he's certainly one of the more patient. When I stopped down about the same time next evening he was in the same spot, seated in his little kayak on a breezy, rainy day. "I've been here all day, right through the rain," he said. "No matter how bad it gets, I figure it's better than work."

With high summer here, vacationing hordes are descending on beaches from Maine to the Carolinas. For many, it's a rare chance to fish. Unfortunately, say experts, high summer is not the best time to catch big ones off the beach.

"We had a real good spring and early summer here for big stripers and weakfish," said Dale Timmons, a native of Ocean City who publishes Coastal Fisherman, a free recreational fishing magazine for the mid-Atlantic. "But when the water gets warm, it's mostly small stuff like whiting, spike trout, spot and a few flounder.

"Then in September we'll start looking for larger stripers and blues in the surf, some speckled trout around the jetties and for the last few years we've had real good fall runs of red drum."

Timmons said the best fishing along the Maryland-Delaware shore, the most popular destination for Washington area vacationers, is on Assateague Island south of Ocean City and on Fenwick State Beach in Delaware. Both are accessible by four-wheel-drive if you buy a special permit, or you can park and walk in at designated spots.

From Timmons's perspective, the key to success is being able to read the water and find sloughs where predator fish are likely to lie. "What swimmers hate, fishermen love," he said, referring to tidal rips where water rushes in and out through breaks in the sand bars near shore.

"The best thing to do is ride or walk the beach at low tide and look for shore breaks, then come back when the tide is rising and fish there till the start of the ebb," he said.

He admitted it's an acquired skill. "I ride down the beach with my brother-in-law," said Timmons, "and I'll say, 'There's some funny water over there.' He says, 'It all looks the same to me.' "

Hodges, the cobia conqueror, said he knew when he sat down the evening of his big catch that he was in a prime place. "I just had that feeling," he said.

CAPTION: Rick Hodges, with wife, Wendy, used kayak to put his bait in position to hook 30-pound cobia in Hatteras, N.C.