Florida tuna fishermen prefer artificial lures over natural baits for high speed trolling.

A hundred-mile trek in an open boat takes on a new dimension when your path crosses the Gulf Stream. Even on calm days, this hard-flowing Atlantic current seethes and writhes, pulsating in reckless rhythm while pushing a steady torrent of blue-black water northward. Mariners' legends recall how quickly the Stream can blow up, tossing wavecrests skyward into frothy, whitewater peaks-beautiful, yet dangerous.

But anglers know that piscine treasures prowl beyond the eastern boundary of the Gulf Stream. Each summer, more and more fishermen outfitted to make the long run are striking gold in the form of yellowfin tuna schools.

It's the kind of fast-paced, energetic fishing that brings dedicated anglers back for more, season after season. In the predawn hours, I arrived at Port Canaveral for my first trip, but by day's end, I would be ready for more.

"Are you bound and determined?" a lone voice, hidden in the dark behind the console gibed. "You gotta be tough to play the tuna game."

It was Keith Lawhun, captain of Barely Rigged. The time? Sometime between three and four a.m. Across the planks, silence hung like an old glove. We were a good two hours ahead of the usual port early birds.

Seventy-five miles of bumpy Atlantic later I was still bound and determined. While bouncing across a particularly nasty stretch, Keith leaned back and said, smiling, "only 25 miles to go." The roar of 450-outboard horses in full rev kept conversation to a minimum. In our crew of five, three of us were first-timers. We witnessed a glorious sunrise. Keith never slowed down. His words as we passed the sea buoy rang in my ears: "You gotta get there to fish there."

After crossing the east wall of the Gulf Stream, Lawhun backed off the throttle long enough to adjust the radar. Following a 3-hour run at 30 knots, the solitary nature of our venture struck me. In all directions, open ocean stretched for miles. Nary a soul in sight. Not even on radar. We were alone, five anglers aboard a slick center console, seeking guidance from the occasional blips echoing across the radar screen.

Lawhun gave us fair warning, gunned the boat, and sped off toward a small, fuzzy, green target pulsing on the radar screen.

"Fish ahead. Get ready. Drop 'em in now!" he bellowed. "They're coming our way."

He pointed at a small blip moving at a fast clip to ground zero-our boat. Birds flew into view, wheeling, dipping and screeching, scant feet above the surface. Under them, the turquoise water churned like a cauldron as yellowfin tuna streaked and struck, sending plumes of water into the air.

Mate Rob Smith spooled out the shotgun offering, a black Todd's Barrel Head lure. He slammed the 50-pound-class trolling reel into gear when a good quarter of the line trailed behind the transom. We ran similar lures tighter-thankfully-from the outriggers, some 75 yards back, and clipped two flatline diving plugs, Braid Speedsters, into place, a mere 40 yards off the stern.

Keith wheeled the boat to port, dragging the lures in a wide arc to intercept the leading edge of the melee. "Watch your baits," he said.

The skipper's words were lost in the high-decibel scream of four 50-wides dumping line as yellowfins blistered horizon-bound under full steam, despite the 15-pound drag strike setting. Lawhun jammed the throttles, pushing Barely Rigged from her 10-knot trolling speed up to 15 or more. He turned away from the pack, eased off the throttle and started laughing, watching his crew performing the cockpit shuffle. Not one of us had anything close to half a spool of line on our side.

We were knee-deep in a cockpit brawl. Tony, A.Z., Rob and I wrestled for every inch of line. Five baits in the spread. Four yellowfins on the hook. On the first pod we encountered. Is making the trip worth it? You bet.

On that July morning, Lawhun's description of using radar to chase yellowfin tuna finally came to jell. At the core of our success was technology. Savvy anglers have discovered that monitoring radar is the most efficient way of locating yellowfins in the wild bluewater yonder. Properly tuned, radar can pick up the seabirds that follow the same types of forage as the tuna schools. Think of it as a way to expand your view from one-half to nearly six miles. It's kinda like using a magnet while searching for the proverbial needle in a haystack.

Two Port Canaveral captains, Ed Dwyer and Mike Kane, are widely credited for developing and perfecting a radar technique for the Florida east coast tuna fishery. In the early '90s, Dwyer's Ticket and Kane's Whitewater broke the ice for what would become a yellowfin bonanza. Their exploits are well-chronicled ("Canaveral's Yellowfin," FS, Nov. '95). In recent years, anglers have been adapting the methods to smaller boats and outboards. Lawhun put in a lot of effort rigging his 34-foot boat to chase tuna beyond the east wall.

He quizzed electronics experts. Most suggested something from the Furuno line. Logging on, Lawhun gleaned information from Furuno's Web site. Durability also factored into his formula. Lawhun needed a unit that would withstand the rigors of repeated high-speed charges across the Gulf Stream.

"Furuno recommended the 1942 radar model, saying it was perfect for the task," he said. "I believe it. We've broken everything on the boat except the radar."

"For power, I chose a 6 kW radar. It's a good match for my boat. A 4 kW will do the job, but it's really not strong enough. Since Barely Rigged is a low-profile hull, 10, 12 or 18 kW units didn't offer any serious advantage. I can't mount them high enough above the water to utilize the extra power."

His choice is a favorite among the radar tuna crew.

A quick tip: If you're thinking about adding radar to your vessel, stick with open ray units, the ones with a revolving T-bar. Steer clear of the dome models for tuna chasing.

Mounted above the deck on a beefy radar arch, the Furuno 1942 6 kW unit gives Lawhun the ability to "see" a flock of birds (out there they're called pods) in any direction from a distance of up to six miles. It will also read pods of two to four birds from two to three miles away.

Getting dialed in is the key to locating birds. On Barely Rigged, Lawhun switches the screen to a 6-mile radius. His procedure incorporates increasing the rain and clutter controls to max to eliminate both. Next, he turns up the gain until a light green haze, or echoes, fill the screen. Back off the gain knob until the light green color just starts to disappear. You're set. Birds will show as tiny, green blips. Often, they'll "blip" on every other rotation until you close in on the target. It takes a few tries to get the setup wired, but once you do, you'll keep your eyes glued to the screen.

Another radar believer is Dave Rogers of Daytona Beach, who fishes aboard the 29-foot Caymar. Rogers cut his tuna eyeteeth hunting for yellowfin the old-fashioned way, relying on eyeball power. Three years back, Caymar's owner, Dave Heine, installed radar, also a Furuno 1942 6 kW. Rogers likes the change.

"With radar we can spot birds, rips and weedlines," he said. "Our vision increased from one-half mile of eyeball power to about six miles." He stresses getting the machine dialed in. "Make sure to turn up the gain enough to pick up birds."