It was a sunny and calm Bimini morning as Harry Vernon III and I headed for a yellowtail snapper spot which, for us, tenders a best-odds guarantee of catching them. However, upon our arrival, things were vastly different.
With barely 1 knot of dirty, green-water flow—versus a moderate royal blue current— we anchored, chummed heavily and crushed cero and king mackerel, horse-eye jacks, big blue runners, ’cudas and other assorted predators, but not a single yellowtail snapper. Something was amiss.
Having Simrad’s StructureScan side-scan sonar technology, which was new at the time, I activated it to confirm the absence of yellowtail prior to leaving. To our surprise, a large “ball” of ’tails appeared some 50 feet directly off my port side console! I made a cast up current of the boat, let the bait drift back to the “ball” and caught a plump yellowtail. Then, it was Vernon’s turn to score.
We alternated catching yellowtail until a bunch were on ice. Were it not for StructureScan, we would have blamed the absence of our target species on poor water conditions. But in reality, the yellowtail were simply gathering far from the hungry predators within the chum slick.
This experience, though many moons ago, continues to serve as a prime example of how potent side-scan technologies are in revealing fish. Sonar technology has advanced significantly since then, but the objective remains the same: Locate fish and you will likely catch them.
More on side-scanning in a bit.
Live Sonar
The latest technology encompasses real-time sonar readings using live sonar, also known as forward-facing sonar by some anglers. Based on ideal conditions, not only are bottom features upwards of 300 feet directly in front of a boat displayed for safe navigation in skinny waters, but also the whereabouts and movements of game fish in real time. That is, when a fish appears on the screen, its exact movements can be scrutinized for precise bait placements, including when they are going for the bait or turning from it.
Live sonar got its initial launch—and the nickname of forward-facing sonar or FFS—in freshwater bass fishing. And soar it did, to where it’s now under major scrutiny, with some tournaments restricting or banning the technology altogether.
Mark Daniels, a high-profile competitor within Major League Fishing’s Bass Pro Tour division, says, “Right now, there’s a lot of hating on it in freshwater tournaments. It seems to go against the sportsmanship and heritage of bass fishing as we know it.”
The bottom line is that it gives an angler the capability of chasing an individual fish for as long as they feel they have a chance at getting it to strike, either out of hunger or aggravation, Daniels reveals. “It’s really that dominant,” he says.
Daniels has a Garmin LDS 34 and recently caught 20 smallmouth bass during a competition within Lake Huron’s Saginaw Bay extension. “I was just trolling along at 3 knots and casting to every fish I saw in real time,” he says “I caught every single one that way.”
It’s so remarkable, you can see your lure appear on the screen and a fish eating it, according to Daniels. “It’s real time, so if you see a fish turning away, you’ll know where to place that next cast to intercept it,” he explains.
How It Works
In live sonar’s basic form, a specialized transducer emits high-frequency sonar waves forward into the water, which are then converted into a continuous high-resolution, live-feed screen display. The whereabouts of fish, the sizes, movements and behaviors can be continuously watched. Daniels reports that in clear waters he can see a bass 110 to 120 feet ahead in depths to 20 feet with his Garmin. In nutrient-rich waters of around 10 feet deep or less, he’s able to spot fish approximately 80 feet away, though the resolution won’t be as sharp.
I had an opportunity to test an early ActiveTarget system from Lowrance with the transducer mounted to a trolling motor. The highlight was seeing a large school of juvenile tarpon in brackish water. We caught and released three up to 10 pounds. The school’s underwater movements were mesmerizing and a show unto itself. More recently, during an ice-fishing excursion on Minnesota’s Lake Mille Lacs, we used Lowrance’s ActiveTarget to locate perch and walleyes and watch their reactions while we teased them into striking our jigs.
Salt Water Intrusion
“It (FFS) is a well-guarded secret among my friends who fish for redfish, trout, flounder and sheepshead,” says Daniels. “Just like we’re doing in fresh water, they’re destroying inshore saltwater fish with this technology, and keeping very tight-lipped about how well it works for them.”
Echoing Daniels’ sentiments, FFS can be a huge advantage for fishing bridges, passes and inlets. Fish whereabouts can be uncovered and their movements watched in real time. Just ponder the coastal-wide species in play with it—snook, tarpon, striped bass, redfish, sea trout, bluefish, snappers, sheepshead, blackfish, groupers, mackerel, California yellowtail and others inhabiting bays, sounds and nearshore waters.
Daniels made an interesting observation—bass in freshwater lakes with heavy tournament activity are wising up to FFS.
“When forward-facing sonar first came out, the numbers of bass caught and released were incredible—big numbers!” Daniels says. “However, after a few years of this, the bass seem to be catching on; they’re now often harder to catch and require more finesse to do so.”
Daniels ponders questions like: Could fish associate vibrations from sonar beams striking them with danger, or are survival instincts of bass kicking in?
Read Next: Live Sonar Benefits for Saltwater Anglers
Side-Scan Success
As mentioned earlier, side-scan technology has proven advantageous in inshore and nearshore waters. Scanning upwards of 300 feet off a boat’s port and starboard sides (independently or simultaneously) and even straight down (down scan) covers a large swath of water. As described in my earlier yellowtail example, it can be a day saver.
Side-scanning continues to boost productivity for gathering baits. When cast-netting pilchards, for example, pushing out the side-scanning distances will lend 300-foot extended views off each side of the boat. Many times, a bait school appears within that cone.
For trolling inshore and nearshore channels and bottom structure, side-scan reveals the exact whereabouts of sunken debris, rocks, dips and abrupt ledges, allowing the helmsman to steer directly alongside or over these potential ambush points. It’s the same with bait pockets and even large bait schools.
I’ve used side-scan countless times to find shallow-water (50 feet and less) structure for jigging or live baiting while drifting, and even anchoring for bottom fish on patch reefs in particular. Add high-definition shaded-relief bathymetric bottom charts to the mix, and it’s an unbeatable combination.
Offshore Weedlines
Basically, the limited cone angle of side-scan is for waters shallower than 90 feet, with its best performance occurring in water depths less than 50 feet. However, Florida Keys offshore guru Alan Wenzel uses the technology when trolling offshore weed lines for species such as mahi.
“With side-scan sonar, I’ll see a good slice of water underneath the weeds and sometimes subsurface debris, bait, the occasional tripletail and even dolphin that aren’t up by the surface,” Wenzel says.
“Being able to view a portion of water down to around 50 feet or so has proven to be a very big deal in this type of fishing, at least for me,” he says.
Ultimately, you might ask, “Should live sonar be penalized or restricted?” I think not. For salt water, we have radar to locate birds (which in turn lead to feeding game fish); powerful traditional sonars and transducers showing canyons, deep bottom compositions, bait concentrations and game fish in explicit detail; and even high-end Omni 360-degree live feed sonar for big game tournament fishing, with a cost north of $100,000.
Furthermore, high-definition bathymetric shaded-relief charts show every nook and cranny along the seafloor for bottom, reef and wreck fishing. The average angler can simply move a cursor over an attractive piece of bottom and run right to it.
It’s called technology, and there’s no stopping it. That being said, it comes down to responsible angling and rules and regulations aimed at keeping our game fish stocks at sustainable levels for us and future generations to enjoy.
