While the underwater terrain of most lakes remains largely unchanged, our means of examining it has evolved dramatically. From a spinning globe to Google Earth; from analog flashers to sonar “x-ray vision,” perception continues to define reality. Anglers are using new-era electronics to solve mysteries and unveil underwater secrets faster than ever.
E. L. “Buck” Perry, who spent years studying the dial of his Lowrance Green Box, offered an insightful comment in 1965 that applies to technology today: “The depth sounder can be a great help, provided you can interpret what it shows. If you can’t, you’re better off without it.” In Perry’s time, flasher “blips” vaguely represented fish, cover, and structure, while today, LCD sonar draws fish arches accurately enough to make a good guess about species. Side, down, and new 360 directional sonar are something else entirely, scanning entire underwater vistas, painting eerily realistic portraits of submerged trees, boulder fields, sunken boats, and fish.
It takes just a glimpse at the giant screens of a Humminbird 1198c or Lowrance Gen2 HDS12 to visualize the potential of directional sonar, particularly side and 360 viewing. Yet when anglers first attempt to decipher underwater layouts relative to their sideways orientation on a monitor, things can get more complicated.
Thankfully, there are guys like Doug Vahrenberg. Among the nation’s most knowledgeable and experienced users of side-imaging technology, Vahrenberg is a touring bass pro and sonar industry consultant from Higginsville, Missouri. Each season, he conducts on-the-water lessons to help anglers comprehend what they’re seeing and how to translate screen orientation into a solid mental image. To begin scaling the learning curve, Vahrenberg suggests spending at least a day on the water studying the screen, minus rods and reels.
“Idle around your favorite spots and study the screen,” he instructs. “Spend time scanning the boat ramp area where you launch. It’s a familiar above-water structure that when seen on screen provides a great visual reference for other underwater objects. It helps you understand the scale, size, and layout of the underwater terrain. You also get an idea of an object’s distance from the boat.
“Don’t be afraid to surf through your fishing electronics settings,” he continues. For maximum screen detail, set Humminbird and Lowrance units to scan 50 feet to each side to provide the clearest picture of objects. But for scanning a wide swath, he recommends setting units to view up to 240 feet on each side.
Next he adjusts range and chart speed. “Match chart speed and boat speed, so if you’re scanning at 3.3 mph, set chart speed at 3. This maximizes the detail of your images. The slower the chart speed, the better the detail. Also, you can freeze the Humminbird screen on a good image, and then use the SI Enhance feature to tweak sensitivity and sharpness, altering the image until you get it just right. You can tune it so fish images jump off the screen.”
Vahrenberg notes that as you gain experience with side-looking sonar, identifying fish becomes easier. Likewise, shad and other baitfish schools often register so clearly that you can count individual minnows. While this is true, it’s also noteworthy that larger 9- to 12-inch screens are helpful for detecting bass, especially fish that are near vegetation, wood, and rock. Positioning the sonar unit near your eyes is an advantage, too, particularly when fishing from the bow. Installing an extension-mount, such as a Toughbar Extension Arm, elevates the unit nearly 2 feet closer to your face. It not only increases visibility of screen detail, but also keeps casting targets in your line of sight. Otherwise you constantly glance away from the water and back to the unit.
I predict anglers will begin actively hunting bass with 360 Imaging, which scans the water ahead of the boat, in addition to the sides and astern. While few anglers have yet experienced Humminbird’s new fish-finding technology (due for release this fall), 360 has become one of the most anticipated techno advances in recent memory. Professional bass angler Kevin VanDam is one of the few to fish with 360 Imaging, and calls it a tremendous time management tool.
“The ability to cast and view the screen simultaneously is huge,” he says. “Unlike side-imaging that requires you to be moving to register a signal, 360’s rotating transducer keeps reading while your boat is still. I can work a flat and look in every direction around the boat. If I mark a stump or a bass swimming left to right over a weedbed, I can fire a cast directly to it.”
Another advantage of 360, says VanDam, is its ability to show you changing contours ahead of the boat. “I can see and follow a channel ledge or breakline as it meanders in front of the boat, and I can do it without driving over it.” Further, when used in conjunction with a GPS mapping program, such as LakeMaster, 360 becomes perhaps the ultimate spot-marking tool. Scan vast spans of water—say a 6- to 10-foot flat in a large bay. Move the cursor over each visible piece of cover—stumps, clumps of coontail, rockpiles, or tiny depressions—and drop a waypoint. A quick run down the middle of a bay soon fills the map window on your unit with every vital casting target in the vicinity. Go back and cast to every spot. Or go into what Vahrenberg calls “active hunt mode,” scanning water and casting to targets simultaneously.
On a recent exploratory outing at Lake Lanier, Georgia, with Humminbird’s Bill Carson, I was astounded by the unit’s ability to reveal and pinpoint suspended striped and spotted bass, and to follow them as they swam in various directions, often in pursuit of shad. By using the 360 screen-scale function alongside traditional two-dimensional sonar in split-screen mode, we could accurately gauge the position of individual fish—distance and bearing from the boat, as well as their depth. Casts to estimated targets with small swimbaits and tailspinners scored numerous bass bites. The rotating 360 transducer, which attaches to the boat’s transom via a Minn Kota Talon mount or a similar product, constantly sends refreshed signals to the screen. It becomes easy to track and follow individual bass and bait schools as they swim. Not only does 360 give anglers the ability sight-fish virtually, placing casts just ahead of moving bass, astute fishermen see bass and baitfish movement patterns, relative to structure, cover, and open water.
For creative anglers such as Vahrenberg and Great Lakes area bass pro Joe Balog, a modified form of full-circle scanning has been possible nearly since the inception of side imaging a decade ago. By mounting a side-viewing transducer to the base of their bow trolling motors (this is possible with both Humminbird and Lowrance products), Vahrenberg and Balog can examine water nearly all around the boat by steering the trolling motor.
The Transducer Shield & Saver (transducershieldandsaver.com), an ingenious mounting device used by Vahrenberg and other pros, precisely positions a side-viewing transducer to the base of the trolling motor. Vahrenberg says that the mechanism aligns and secures the probe in place, to deliver the clearest screen signals. The Shield & Saver also protects expensive transducers from bottom impact, creating a seamless protective “shell” around the probe that also prevents vegetation and debris from collecting on it. “For scanning shallow water around wood, rock, or vegetation, it’s essential,” Vahrenberg says.
“When I’m in hunting mode,” he continues, “I can scan shallow water all the way to the bank, including shallow timber and minor bottom divots that can hold bass. The screen even shows me the position of trees on the bottom, which allows me to optimize my casts and retrieve angles.” He also peeks under boat docks to determine which ones are holding baitfish and bass.
Balog, who ran one of the original side-imaging units, has successfully integrated the technology on his home lakes, Erie and St. Clair, as well as southern reservoirs. For finding fish in vast unfamiliar water, Balog says side-viewing is indispensable. He runs transducers and separate sonar units on both the transom and the bow. While cruising along at 4 to 6 mph with the big motor, he checks unfamiliar water with wide scans of 240 feet in each direction. He’s hoping to catch a glimpse of a potential structure—a portion of a rockpile, bottom transition, or isolated weed patch that holds gobies and smallmouth bass.
Once he’s glimpsed a section of one of these spots, which may be surrounded by acres of empty water, Balog uses the trolling motor to go into hunt mode. Setting his bow graph unit to scan 50 feet of each side of the boat, he gets clearer views of terrain, including cruising bass. He’s hoping to discover the juice, his term for subtle sweet spots that attract big bass. Often, it’s a single boulder on a rockpile, a high spot on a point or a wreck; or even something as subtle as a bottom seam carved by a glacier. Nothing unveils the juice quite like modern sonar imaging—correction, almost nothing.
Real World Views
As attached as many of us have become to side-viewing sonar, I still keep an underwater camera in my boat’s storage. A surprising number of bass pros employ cameras, too, although sponsorships with other companies often prevent them from talking about it. You sometimes mark sizeable fish or scan a particular area with sonar, but remain unsure about what you’re seeing. A camera deploys quickly and easily, and modern high-resolution optics and LCD monitors, such as those in my MarCum VS825SD, display live video in dazzling color and quality.
In 2010, FLW bass pro Troy Morrow used a MarCum camera to help secure two major wins and a $50,000 payday at the Forest L. Wood Cup on Lake Lanier, Georgia. “At Lanier, the camera helped me identify key brushpiles and eliminate non-productive ones during prefishing,” he says. “It also showed me bottom composition around brushpiles and brush thickness, as well as the quantity of baitfish using each pile. The camera revealed which species were present. Some of my sonar returns looked promising, but they were mostly crappies, stripers, or catfish. Others were loaded with small bream and spotted bass. But a select few held numbers of bigger largemouths. The camera gave me a tremendous amount of confidence that I was fishing brushpiles that held the right bass.”
Although underwater cameras are not allowed in B.A.S.S. tournament competition, FLW and most other circuits allow them during prefishing. “In tournament practice, when you want to find specific spots, but don’t want to hook fish or show your competitors what’s there, the MarCum VS625SD is a great tool,” he says. “I hold over deep structures with sonar, then lower the camera to see exactly what it looks like—how the cover is positioned, what’s living in it, and the size of any bass in the vicinity. But don’t burn the spot by hooking fish before the tournament begins.”
Beyond the camera’s ability to provide real-world views of the terrain—at least in moderately clear water—some of the newer systems, such as the MarCum LX-9 and Aqua-Vu 760cz provide on-screen displays of water temperature and camera depth. I’ve often used the camera to find bass and the on-screen temperature and depth displays to discover fish preferences.
During a stretch of brutally hot weather this past summer, we used the camera to pinpoint a bonanza of big smallmouth and largemouth bass along sheer vertical walls of pondweed and coontail. While surrounding waters from the surface down to 15 feet registered 79°F to 83°F, we discovered a pocket of 74°F water at the base of the vegetation in 17 to 20 feet of water. Nearly everywhere we found thick vertical vegetation at this depth, the water was cooler and it had attracted an abundance of sizeable bass, which willingly bit jigs and drop-shot rigs.
- One of our favorite features on this new dual-frequency sonar unit is the Accu-Fish function, which not only recognizes whether it’s pinging individual or multiple fish, but also computes echo strength to estimate fish size from 10 to 199 cm at depths of 2 to 100 meters. Also cool, the FCV-587’s Bottom Discrimination feature tells you if the major bottom composition is rocks, gravel, sand, or mud. We also like the White Line technology, which distinguishes fish from bottom by changing the strongest signal color to white. It also helps judge fish school density. Other nice touches include a bright, 8.4-inch color LCD that you can see even at odd angles while wearing polarized glasses. $1,695. furuno.com
Angling technology is something of a paradox. The more we learn about bass and their habitat, the more we realize how little we really know. That’s the beauty of it. No matter how sophisticated fish technology becomes, we always want to expand the window.
*Cory Schmidt, Brainerd, Minnesota, is a versatile freelance writer and frequent contributor to In-Fisherman publications.