The other day Cowchip joined us for dinner at a seafood joint in Annapolis. He's from the Midwest and doesn't know a rockfish from an oyster toad, but we don't hold that against him as long as he doesn't embarrass us talking about it.

However, somewhere between the crab soup and the fried oysters Cowchip piped up in his languid drawl and asked another one of those sad, landlubber questions for which Midwesterners are famous.

"Shucks," he said, "one thing I allus wunnert was when you go out a-fishin' how you know where it is that you're a-sposed to drop your hooks over at?"

After we got through groaning and throwing crab gurry at him cousin Turlock tried to fill him in on some of the finer points of Bay fishing.

"You got to line up your shore marks," he said. "See, crabs and oysters, they just go along the bottom. They got their north- south routes and their east-west routes. But fish don't have to crawl. They can go wherever they please.

"A lot of times fish get to swimming around looking for something to eat and they get lost. Each different kind of fish has certain shore marks he'll look for in the evening so he can find some other fish like him to stay overnight with.

"Rockfish lay up between pine trees." Turlock pointed out the window to the creek. "See that pine over on the other side? Well, you go out in your boat and go up and down the river until you find a pine on this side. Then put your boat right in line between the two pines and start catching."

Turlock said different fish have different shore marks. Bluefish lay up between water towers; perch favor blinking red shore lights and sea trout, which are latecomers to the Bay, line up between the nuclear power plants.

"That's fine for fishing at darktime," said Cowchip, "but what about us fellers what doesn't like going out in such perilous circumstances like when you can't see where you're a-going?"

When we got done guffawing and peppering him with clam snouts old Dexter Chickennecker hollered out for silence so he could explain a thing or two to the landlocked fool.

"What do you think they make charts for?" he said. "The charts tell you where the fish are at in the daytime. Every year they move around a little, so you have to buy your updated Fishing in Maryland and your Fishing in Virginia new every year.

"Then if you want to catch a black drum, you just flip through the pages till you find a picture of a black drum, and then you sail to the place on the Bay where that picture shows it, anchor up and drop your bait over."

"Now there's another thing what has me perplexed," said Cowchip, "which is how you figger what to use for bait."

We all got a good chuckle over that and when we got Cowchip dried off from the oyster broth Turlock dumped over him Cousin Crabtrap tried to elucidate on the bait theme.

"See, it don't matter what you use," Crabtrap explained. "Just whatever you got, whether it's menhadens or alewives or even bunkers. It all works the same. But your technique, that's what separates the catchers from the fishers."

Crabtrap said his favorite technique was chumming. "I always takes a good buddy along," he said, "and after we get to the spot where Fishing in Maryland says the fish are, we take a little time and have a couple of beers, just to loosen up.

"Then me and whatever buddy I got along, we get back in the stern side by each, and he puts his arm around me and I puts mine around him, and we starts singin' whatever happy songs we can think of, real chummy like.

"Meanwhile, we're fishing away and the fish wonder what all the happy commotion's about. We keep the bait bouncing right in time with the music and when they come along, they just can't resist."

Cousin Crabtrap said if you can't get a buddy to go along, you can go chumming over the CB radio, which is why CBs are so popular with fishermen.

"Well shoot," said Cowchip, "what if you're like me and you don't have any buddies or a CB radio, either one? How you catch 'em then?"

Oystershucker had a half-conniption over that one, but by the time we got the osyter spat out of Cowchip's hair he'd settled down enough to help him out.

"That's when you go trolling," said Oystershucker. "If you can't chum, you troll.

"Trolling," he said, "is short for con-trolling. It means you got control of your bait to make it swim where you want it to. Just like them radio-controlled sailboats or cars, you have your little gadget on the boat and you swim your bait around until she gets close to a fish, and then you're in business."

I smiled at Cowchip. "Now that you know all about the Bay, and all about chumming and trolling and shore marks and charts, do you think you can relax, pipe down and finish your dinner."

"Yep," said he, pointing to the crabcakes. "Now how's about passin' me some of those hush-puppies."