This much is certain - when you pull a cobia into the boat, it's best to be keenly aware of the potential consequences.

Don Hammond discovered this several years ago on the Broad River when he and a fishing partner found themselves sharing their boat with a cantankerous 48-pound cobia.

"It smashed a large tackle box," Hammond said. "We had Cisco Kids and spoons going everywhere. I was standing on the bow, the other guy on the motor - the fish had the boat."

Lesson learned.

"You need to treat these fish with respect," Hammond said.

As gallant a battle as cobia wage when hooked, their fight seldom subsides when they're finally wrested from the water. Count Darrell Crabtree among the many fishermen who have discovered this trait.

"I've had to jump up on my motor a couple of times, too," said Crabtree, a Charleston-based inshore guide who has been catching Broad River cobia for 20 years. "I've seen some pretty hilarious things down there. One guy in a small Boston Whaler got a fish to the boat - his rod in one hand, a gaff in the other - and pulled it into the boat. The fish went crazy, and he ran to the front of the boat. It knocked coolers, rods and reels out of the boat."

Preventing one's gear from going overboard may be a worthy goal, but the primary quest is enticing a bite from a boisterous cobia.

There's no better place for such action to unfold than the Broad River, an aptly named body of water that dumps into the Port Royal Sound north of Hilton Head Island along South Carolina's southernmost coastline.

These Broad River bruisers have spawned quite a fishery, as the congregation of boats along the river during the month of May will attest.

"On any given weekend day in May - Saturday or Sunday, it doesn't matter - you'll see well over 100 boats in the Broad River chasing cobia," said Hammond, a marine fisheries biologist who operates a private fisheries-research company in Charleston.

The cobia have always been here, as many long-time local anglers will confirm, but the fishery has gained widespread popularity and notoriety only recently.

"It has really blossomed in the last decade," Hammond said. "If you're going to go after cobia, you're talking Beaufort County. Eighty-five percent of all cobia caught in South Carolina are caught there. It's an incidental fishery in other counties. The only other place there's a regular, productive fishing spot, is at St. Helena Sound in Colleton County."

Crabtree, who is also a professional redfish angler, makes two or three trips each week to the Broad River during May, and he has seen his company grow exponentially in recent years.

"There were a handful of people in the early days fishing for cobia, but really, in the last four or five years, it has just exploded," Crabtree said. "Now, every weekend, you'll have dozens of boats coming from Charleston. And I know folks who come down every weekend from Columbia to go."

Not that Crabtree minds. In fact, he maintains that the abundance of anglers only adds to the fun.

"It's fun being around all the other boats," Crabtree said. "Everybody's hollering and cheering when someone gets a fish on. Camaraderie is a big part of cobia fishing on the Broad River. It's not every day you can go onto a river like that and catch an ocean-going fish.

"But it can be real intimidating when you go for first time. You may be out there with 75 boats, but for the most part, everyone's real courteous. They'll cut their lines if you've got a fish on. You've just got to remember to be patient, courteous to others, and pay attention to what's going on."

Adding flavor to the mix is the mixed bag of vessels one is likely to encounter while grouped up in a cobia caravan: 14-foot john boats side-by-side with 50-foot sportfishermen.

"You're liable to see anything out there," Crabtree said.

For the most part, the cobia frenzy is a one-month phenomenon. Anglers have been known to catch cobia as early as mid-April and on into early June, but May is prime time.

Hammond said that much about cobia movement remains uncertain, but he's concluded that the fish move into the Port Royal Sound and the Broad River in a "prespawning aggregation."

"I think they're coming in to feed on crustacea," Hammond said. "They need that in their diet just prior to spawning - possibly to produce higher oil levels for egg production."

The fish may leave the sound for a day or two, Hammond said, to spawn around coastal reefs, but they return and move upriver. During May, cobia may be encountered along much of the 13-mile stretch from the fall of land up to the Highway 170 bridge, a well-known location that provides easy boat access via the Broad River Landing. This may be the most popular location, but there are plenty of other favorite hot spots, including the Turtle, Cobia Hole, the Christmas Tree and the Rip. None will be difficult to find.

"It's a wide area to potentially spread out over, but somebody who doesn't know where to fish won't have any trouble identifying where they should be - just look for the other boats, then try to find an open spot to anchor up in," Hammond said. "Where most people are anchoring up is anywhere from eight feet deep to maybe as deep as 30 feet, but if you have to anchor any deeper than that, you're in the wrong place."

Specifically, fishermen should look for areas with unusual bottom features that cause an upwelling of currents. Crabtree tries to locate the top of a sandbar that drops off into a deep hole or where deep water comes up onto a shelf. Once anchored, he uses a Sabiki Rig to catch fresh bait - typically thread herring, or "greenies" - and drops two baits straight down off the back of the boat, then two baits farther back. He also drops a mesh bag of fresh chum off the front of the boat, with a weight to keep it to the bottom.

His tackle is simple and standard saltwater fare - 20-pound test line, No. 2 circle hooks, a 5-foot leader of 50-pound test and a weight that may range from one ounce up to six ounces, depending on the current.

While greenies are popular, anglers may find success with a variety of baits, including cut mullet, menhaden, crabs, squid and eels. Crabtree is fond of cooling his eels on ice for a short time before hooking them.

"They'll become dormant, making them easier to hook, then as soon as you put them in the warm water, they come back to life," Crabtree said.

Due to a cobia's varied diet, Hammond refers to them as "trash cans."

"They mostly feed on crabs and shrimp, but they'll suck up a fish in a heartbeat," Hammond said. "I've pulled everything from catfish to even spiny boxfish out of their stomachs. But they do have some preferences."

Crabs are an excellent choice, but Hammond is quick to remind fishermen that legal-sized crabs must be broken in half, because state regulations don't permit the retention of undersized crabs. And Hammond seldom goes cobia fishing without squid.

"In case they don't chase threads or menhaden, I'm going to have squid, too," Hammond said. "And at the end of the day, you can take them home and put them in the freezer as insurance for your next trip. I've had some days when I've had some of the prettiest baits out there and they won't touch them - but they'll hit my old leftover baits. You never know what their tastes are going to be geared toward.

"I equate some of the cobia with an old turkey. Young turkeys can be stupid - you can call them and they'll run over and commit suicide. But some of the older ones, you can't coax them in for anything. Some cobias are like that. I will not present the same bait to a cobia more than three times. If he hasn't taken it by then, you need to try something new, because he's not interested."

Timing can be all-important, too. Both Hammond and Crabtree say that fishing the "turn of the tide" is key.

"That's what everybody focuses on," Hammond said. "There's not much difference between fishing high or low tide. It's when that current slows up that's the key - an hour either side of that tide change."

When a cobia is hooked, nearby anglers typically cut their lines or get them out of the water immediately to avoid causing problems for the fortunate angler. It's also a good idea to attach a float to your anchor rope so that a big fish may be pursued without having to pull anchor.

Another burgeoning technique for hooking Broad River cobia is sight-fishing. The water must be calm, Crabtree said, and it helps to get as high a vantage point as possible, with casting platforms providing the ultimate advantage. He'll catch cobia on the fly by tossing large streamers at them, and he also hooks them with spinning tackle, with his preferred lure being an artificial eel on a jighead. Other productive lures include Top Dogs, swimming Rapalas, MirrOLures and bucktails.

"You'll see the cobia cruising right under the surface," Crabtree said. "They look like a big brown log floating around. When you see your first one, you don't realize that you're looking at a fish. Then you say, 'Wait, that thing's swimming!'"

Crabtree is convinced that sight-fishing is more productive on an incoming tide, and he'll work the river in a zigzag pattern, because he's encountered cobia along the shoreline as well as in the middle of the river.

He'll use his trolling motor or idle slowly with his outboard, scanning diligently for a surface-cruising missile. Cobia tend to be rather curious by nature, and they have been known to swim up to boats, despite the noise.

"You can get pretty close to them without spooking them," Crabtree said. "I just try to cast three or four feet in front of the fish, and they'll usually hit it. It can really be a rewarding and productive way to catch them - and exciting, too. When you're sight-fishing, it becomes more of a hunting thing."

Some days, the hunting - and fishing - is better than others. Crabtree's top personal catch weighed in at 56 pounds, but he's had clients on his boat catch cobia in excess of 60 pounds. Two years ago this May, Crabtree caught two over 50 pounds and three others in the 40-pound range in a single day.

The state-record cobia is an 87-pound, 13-ounce giant pulled from the Broad River in May 2005 by Steve Schlader of Lake Barrington, Ill. The average Broad River cobia is in the 25- to 30-pound range, but all of them wage a worthy fight.

"They're exceptionally strong and stubborn," Hammond said. "They have good runs in them like tuna have, and they have the determination of amberjacks. They will definitely test an angler's stamina."

The S.C. Department of Natural Resources has stocked approximately 60,000 cobia into the Broad River as part of an ongoing tagging project that began in 1989. The DNR hopes to learn more about the species' migration patterns and why the area has emerged as such a vital hot spot for the fish.

"Research will provide us with insight as to why cobia are moving back into the estuaries - whether it is to spawn or feed - and why the Port Royal and St. Helena Sound estuaries are of particular importance to this species," said Mike Denson, a DNR scientist.

The research also should provide additional information on how to best manage the fishery.

With the recent boom in the fishery's popularity have come concerns about overfishing. After all, with a 2-fish daily creel limit (and 33-inch minimum fork length), a boat with four anglers could leave the landing with 250 pounds or more of fish in a single day. Both Hammond and Crabtree are counting on individual angler's restraint to help preserve the cobia, which are held in high regard as table fare.

"How much fish can a person eat? How much is enough?" Hammond said. "We're going to have to ratchet down that creel limit in the future because of increasing demand."

Crabtree will keep a couple of fish each season for himself and will allow his clients to keep a fish if they so desire, but he's all for conservation.

"We may need to come up with some better rules and regulations," Crabtree said. "The cobia is a real prolific fish that breeds and grows pretty fast, but people can't keep everything they catch.

"I think for the most part, people use common sense and are releasing a lot of fish. Most anglers are pretty cool about it."

Gaffing is permissible if you have a large cobia you intend to keep, but in other instances Hammond recommends netting the fish.

"What I encourage people to do is buy the largest dip net they can find," Hammond said. "With a little practice, you can net a 60- or 70-pound cobia without a problem. You will get wet, but they calm down quicker, and you've got them under control immediately.

"They'll come to the boat early in the fight, about one-third of the way through, and when they make that pass by the boat, you can have them then if you're good with the net. Otherwise, the fight just really starts at that point.

"It's important, because you are going to catch undersized fish and have to put them back. We have seen through tagging that these fish come back to the same areas, so you've got a chance to catch that same fish in a year or two when it's legal size."

Enjoy, not abuse, is the message. And no one believes in that more than Crabtree, who hopes to be a Broad River regular every May for another two decades.

"We're really blessed here in South Carolina to have that fishery," he said. "It's just a shame it only lasts for about a month, though."