(FORTUNE Small Business) – Thirty yards off the stern, a dark shape rose against the surface, and the mates yelled, "Bella, bella, bella!"

Pesca bella. Sailfish.

Its high dorsal fin cut the water as the sailfish chased a "teaser," a hookless lure being trolled behind the boat. The captain throttled down and steered the big boat to put the stern directly toward the charging fish. A mate madly reeled in the teaser, drawing the hungry fish closer and closer so that I could make a single, deal-making cast with the fly rod. At the last second the crew yelled, "Cast, cast," as the mate yanked the teaser line away.

As if trying to crack a long coach whip, I brought the big fly rod back, then forward, and slung a six-inch fly--actually more like a bird--to the side of the sailfish's head. The fish surged on the surface, chomped the fly, and turned away. I set the hook by yanking the rod to the opposite side of the fish's turn and held on tight.

A hundred yards of line burned off in about five seconds, and the high-voltage power of this creature traveled down the graphite rod, shaking my spine. Pacific sailfish average about 100 pounds and are among the fastest aquatic creatures in the world, capable of 60-mph bursts. The thrill of the fight hits when you feel yourself connected to a fish that big, that fast, going airborne.

This battle played out in the majestic blue water 18 miles off the western Guatemala coast, where a charter-fishing company called Sailfish Bay Lodge just opened a newly expanded facility. The 500-foot depths here are a sailfish breeding ground, teeming with them year-round, making it one of the best sailfisheries in the world. (Blue marlin, dorado, roosterfish, and yellowfin tuna are also abundant.) In 13 hours over two days, I caught and released the first nine sailfish of my life, all of them with a fly rod, and missed at least as many.

Fly-casting for sailfish is harder than using conventional tackle. In the latter, the sailfish go after baited teasers rigged with hooks, and the mate doesn't hand you the rod until there's a fish on the line. In fly-casting, the fish are drawn in by hookless teasers, and when they are near the boat, you cast your fly close enough to get them to bite. The angler must be able to handle a big fly rod and a good deal of line, then react in a flash to set the hook before the fish realizes the fly isn't real and spits it out.

Sailfish Bay Lodge is run by two determined Americans, Robert Fallon and Scott Ruprecht. Fallon, 50, a former construction manager, first came to Guatemala in the 1990s on a sailfishing jaunt. He noticed that there was only one big charter-fishing outfitter on the country's Pacific coast, the pioneering Artmarina Fins & Feathers Inn. (F&F has been running its Guatemala sailfish operation since the early 1990s and has recorded world-record catches.) "The fishery was so good that something kept tapping in my head: Do this, do this--start an outfitting business," says Fallon, 50.

He began organizing fishing trips to the area, which is how he met Ruprecht. Ruprecht, 32, himself a refugee from corporate America (Deloitte & Touche), launched a fishing-tour business called Sportfishing Worldwide in 1998 and now runs trips to spots from Belize to Iceland.

"I knew in my heart I wanted to run my own business, because I was enamored of true entrepreneurs--the Richard Bransons, the Michael Dells," Ruprecht says. "They all started young. I wanted to roll the dice." A number of major corporate clients have arranged trips through Sportfishing Worldwide, including Carolina International Trucking, Miller Brewing, and R.J. Reynolds. Jeff Fisher, head coach of the NFL's Tennessee Titans, was another satisfied customer.

Fallon spent a few years booking trips through Ruprecht's charter company before deciding that a full-on partnership would make more sense. In August 2004 the pair, with two other private investors and American bank financing, broke ground on a $500,000 project to build an upscale fishing lodge on the black-sand beach at Puerto Iztapa in Guatemala. The construction was completed in February.

The new facility, 90 minutes from the airport in Guatemala City, has two main bungalows with four bedrooms each, all in stone and stucco. The open-air bar and swimming pool sit right on the beach, looking westward toward the Pacific. Fallon, knowing that there are few decent restaurants on Guatemala's west coast, managed to hire away a five-star chef from a Cancún resort to run the restaurant at Sailfish Bay. Even at full capacity, the new facility houses just 20 guests, so there's no risk of feeling crowded. The lodge's fleet consists of two boats--both 32-foot Blackfins with twin Caterpillar diesels. A four-day trip, including lodging, food, transportation, and boat, costs $2,830 to $3,700 a person for a four-angler group.

Fly-fishing for sailfish does not require spectacular talent--just determination, a willingness to be taught by a good crew, and a packet of Dramamine. The crew on my boat--Captain Victor Manuel Ceballos and mates Alex Batres and Enio Fajardo, all in their 20s--were terrifically talented and quick, especially in the way they worked the teasers to keep the fish close to the boat and interested.

On my first day out, two sailfish came up chasing teasers simultaneously. (Sailfish often travel in pairs or small schools.) A teaser has a coffee-cup-shaped head made of hard plastic and a long, flashy skirt of plastic ribbon; it resembles a squid when cast out and trolled on a heavy conventional rod. The mates constantly had two teasers trolling close and a third at a distance, and in two days of fishing they managed to draw almost 40 sailfish to the surface.

I cast to one fish and hooked it, and then Scott Ruprecht made a cast and hooked his as well. We shuffled back and forth on the rolling deck, ducking each other in a clumsy limbo as the fish crisscrossed in the wide blue plain behind the boat. Ruprecht's fish ran for El Salvador as I got mine close to the boat, but three times my fish thrashed away before Batres could finally reach down to grab the slashing bill and get the hook out.

Each time the fish darted away, peeling line as fast as in its first run, profanities in Spanish rained down on it. Finally Batres slipped a fighting belt around my waist so the Cam Sigler rod, which was jammed into my hip, could be seated more comfortably, and I brawled for 15 more minutes, bending the heavy-duty rod like a hairpin to slow the fish and gain line. By pure coincidence, Ruprecht and I boated our two fish simultaneously. (Everything we caught was released right away; sailfish aren't very palatable, and in 1999 the government of Guatemala, spurred by the region's nascent fishing-tourism industry, passed a total catch-and-release regulation for all sailfish caught through charter-fishing outfitters.)

All billfish present a danger when brought to the boat because of their leaping ability combined with that saber snout. Sailfish Bay has not seen any major impalings or other accidents, but Fallon did say that a marlin once leaped randomly out of the water straight toward a boat full of clients. "The fish wasn't hooked--it just came up out of the ocean and was airborne, flying right at us," he said. "We thought it was coming right into the boat--it was that close."

The gear used to cast to and battle the fish is the heaviest in fly-fishing--14-weight line and rods, nothing like the four-weight equipment you see on a typical trout stream, though the principle is the same. The flexing action of the rod throws the line, unlike conventional tackle, in which the weight of the lure or bait carries the line off the reel when you cast. Big-game fly-fishing reels must be of Swiss-watch quality or they will simply fall apart under the stress. The $600 Billy Pate "Marlin" model I was using is one of the best available.

The fly-fishing record at Sailfish Bay Lodge, set by two anglers last year, is 22 fish boated and released in one day. The conventional-tackle record was also set in 2004, by two anglers fishing over three days and releasing an extraordinary 134 sailfish.

The high season for sailfishing runs from late October to early June, but fishing for the sails, marlin, and dorado is fairly steady all year, and you can often find better package deals in the summer. Bear in mind that if you go for the beach and food, not the fishing, there isn't much else to do on this part of the coast--no nightclubs, no bars, few other Americans as far as the eye can see.

Why do it? Because authentic, primordial encounters with big, prehistoric fish are rare. Because the first time you see a sailfish leap from the water, your mind is cleansed of everything but the beauty of that sight. And because weeks afterward you'll see sailfish cruising just under the surface of your dreams.