The movement of the cork floating along the edge of the marsh was the normal wiggle caused by a dangling shrimp.

With a myriad of fish species infiltrating inshore waters during the summer, I figured the shrimp was being harassed by an ornery pinfish or tiny shark.

The cork moved with the tide and occasionally danced. In the blink of an eye, it submerged. While I hoped for a redfish or spotted sea trout, I knew a pinfish had finally dialed in on the hapless shrimp. As I got the fish near the boat, it wasn't what I had wished for - nor was it what I had expected.

The faint black vertical lines and the silver body immediately cried sheepshead, a likely possibility, but the lack of visible dental work, a down-turned mouth and tiny chin whiskers gave the fish away as a black drum, a cousin of the state's more popular red drum.

Once I recognized it, I was pleasantly surprised. I had caught several, but it had been a while since the last one.

Black drum are a common saltwater fish whose scientific name aptly describes it. Pogonias cromis is Greek meaning "bearded" and "to grunt." The species has conspicuous chin barbels that give it a sparse goatee, and it utters a long grunting sound, especially when spawning.

Black drum live from southern New England to Mexico; they are commonly caught from New Jersey southward. The species is the largest member of the drum family on the Atlantic Coast, reaching 5 feet long and weighing more than 125 pounds.

Due to the fish's prevalence, if you have spent any time fishing in Lowcountry waters, you have probably caught one. Black drum are widespread, being found in the marsh, surf and deep channels. Where they are found also dictates the size fish you are likely to encounter.

"You can catch black drum of all sizes around here," said Capt. J.R. Waits of Fishcall Charters (843-509-REDS or www.fishcall.com) in Mount Pleasant.

"Fish averaging 2 to 10 pounds can be caught along the grass edges of the marsh with shrimp. Out by the jetties of Charleston Harbor, you'll find fish from about 15 pounds up to 45 pounds or so. If you look around some bridges, the fish are even bigger, with many over 40 pounds."

Admittedly, the only size black drum Waits hasn't been able to find are the fish that run in the 10- to 20-pound range. That's fine, since most of his black drum time is spent pursuing the big ones.

"You can catch the big black drum any time it is warm," Waits said. "From April to November is a good time. I've never caught any big ones in the winter.

"If I had to pick a best time it would probably be during May and June."

No matter their size, black drum are a fish of the bottom. Their pronounced chin barbels act as feelers as the fish moves over the bottom. Favorite prey items include clams, oysters, mussels, crabs, worms and some fishes. Like sheepshead, black drum have strong throat teeth, known as pharyngeals, that are capable of crushing the shells of prey to make them easier to digest.

"For the big drum, you want to think deep and near structure," Waits said. "You can target the fish at any of the local bridges in water 25 to 40 feet deep."

Waits listed the Cooper River Bridge, bridges of the Mark Clark Expressway (I-526) and the Hwy. 41 bridge over the Wando River. Other possible locations would be the James Island Connector and Ashley River Bridge. Before anchoring near any bridge, be certain to inquire with local officials about security restrictions.

"What I like to do is anchor upcurrent of the bridge piling so that the baits will be at the structure on the bottom," Waits said.

Waits uses a 6-6 Ugly Stik rod with a baitcasting reel to get his baits in position. The main line is 30-pound monofilament, but he said that braided line would work as well. A fish-finder rig with 3 feet of 50-pound monofilament or fluorocarbon line and a No. 6/0 or 8/0 circle hook completes the setup. Waits has used line as heavy as 80-pound test, but he has noticed he gets more bites with the 50-pound-test line.

"The amount of weight you are going to need depends on the current," Waits said. "I have used as little as 2 ounces or as much as 12 ounces. You will have to use heavier weights around the new- and full-moon tides.

"I normally fish for black drum about an hour-and-a-half on either side of a tide change. It doesn't matter whether the tide is switching from high to low or vice versa; just fish through the change and into the other side."

Waits said the bite seems to drop off during the middle of a tide cycle. He doesn't know whether the fish stop feeding, can't find the baits as well or if it's because it is more difficult to keep the baits in position in the swift current.

Waits' favorite baits are a blue crab or a - blue crab.

"I only use blue crabs," he said. "I know other people use clams and oysters or shrimp with success, but I stick with blue crabs. Cut menhaden may work as wel,l but it seems to lead to a lot of rays for me.

"For big black drum, I prefer crabs 6 to 8 inches long from point to point. I run the circle hook up through one point about an inch in from the tip where the shell is about an inch wide."

Before Waits drops a crab to the bottom, he will partially crush the top of the crab's shell with the heel of his foot so that it gives off a little extra juice.

"The bite of big black drum surprises many people," Waits said. "A 40-pound fish bites a lot lighter than you would think.

"With my baits on the bottom, I set the rods in free spool. Once a fish picks up a bait, I let them mouth it for a moment before I engage the spool. Remember, since you are using a circle hook, you let the fish hook itself rather than you setting the hook.

"That said, once the fish is hooked, you will want to get it off of the bottom very quickly. Otherwise, if it gets back to the bottom he is going to get around, something and you'll more than likely lose him.

"I use a tight drag when I'm fishing around any bridge."

Besides bridge pilings, Waits had another suggestion.

"It is a good idea to ride around bridges and keep an eye on your depthfinder. Sophis-ticated electronics can pick up debris that has fallen off of a bridge or dropped overboard during construction. Black drum will hold on these spots too."

Waits catches his largest black drum around bridges; his largest to date is 71 pounds. Despite the attraction of bridges for big fish, he still finds them in other spots.

"You can find some nice black drum in the channels on the way out to the jetties," Waits said. "The fish won't be as big, but they still will range up to 45 pounds.

"The best spots are on the edge of a channel - but on the deeper side of the break. The black drum will be on the deeper side, whereas big red drum and sharks are usually on the shallower side.

"When I'm fishing in the channels, I use the same rig that I use at the bridges," Waits said. "I only use a half of a crab since the fish are usually slightly smaller, and I normally scale down the rods to 20-pound spinning rods.

"Because there are no pilings for the fish to get hung up on, you can fight them longer on the lighter tackle and don't have to horse them up as fast. The only place they really have to go is over the edge of the channel."

Another angler who has a knack for catching big black drum, especially on light tackle, is Lee Moyer of James Island.

"I fish for big black drum with 8-pound-test line," Moyer said. "When you use light stuff, you may spend up to an hour before you see the fish. Plus, you end up losing a few that you never see."

Similar to Waits, Moyer uses a level-wind reel, something like a Penn 209, on a 7-foot Ugly Stik rod.

"These are not fast-running fish, so you don't need a reel that can retrieve a lot of line in a hurry," Moyer said. "You can follow them with a boat if you need to. The most important thing is to have a real good drag. If it hangs at all, you risk popping the light line."

Moyer's main black-drum rig is a Carolina rig. He uses 4 to 5 feet of 80- to 100-pound monofilament line for a leader and a No. 7/0 to 9/0 straight shank hook. He said he's never tried using a circle hook for black drum.

"I use blue crabs for bait," Moyer said. "I usually use half of a crab. I've used smaller sized crabs in the past. I didn't see any difference in the number of bites I got but with a smaller crab the rig seemed to get tangled up worse. You can't risk having knots when you use light line."

Moyer has been fishing in Charleston Harbor for over 50 years, and during that time he has seen some changes.

"The places you catch big black drum are around bridge pilings and along the deeper channels," he said. "You can also find them on live bottom areas of the harbor but so much has changed.

"It takes a lot of time to find these sorts of spots. You locate something that looks promising, and you fish it. You fish it today. You may or may not catch a fish. Still thinking it's a worthy spot, you sit on it again the next time to investigate it.

"Eventually you have to give up because you'd like to catch a fish from time to time. So unless a spot produces the first time on it you've invested a lot of effort to locate the good spots.

"I've lost a lot of areas in the harbor," Moyer said. "Security areas have eliminated some as well as harbor dredging. The dredging has eaten up a lot of live bottom areas that I had."

Moyer said when you are fishing in these deeper live bottom areas you must be precise.

"Black drum fishing is pretty physical. I'm constantly re-anchoring so that I'm positioned in the right spot.

"A lot of the good black drum spots are red drum spots too, only the black drum are deeper," Moyer said. "It's a very small area that the black drum are found, and if you are off by 50 feet you end up hooking a big red drum. That's fun but not when I'm using light tackle."

Moyer's best bite has come on either side of the slack tide, the same as Waits' experience. Moyer felt like there was less pressure on the fish during the slack water and it allowed the drum to search for food without having to work too hard.

The big black drum fishery is exclusively a catch-and-release endeavor since these behemoths have no food value. While black drum will never supplant red drum on the top of the popularity list they do offer a chance to catch a real big fish inshore.