By Kevin Tate
Electronic depth finders have been standard equipment on bass boats for decades, but recent advances in what that branch of technology can offer is opening up a whole new world from the waterline down.
In addition to standard sonar, specialized arrays that scan sideways to cover wide areas and scan down to show much greater detail have changed the game.
“Side scan and down scan are only two or three years old, and it’s revolutionized what you can see,” said Jim Long, of the Brewer community in Lee County. For Long, a retired Itawamba Community College physics professor, both gathering knowledge to feed his own curiosity and sharing that knowledge with those willing to learn are lifelong passions. Adding a love of bass fishing to the mix makes a recipe he’s happy to share. His many decades on the water putting the evolving technology through its paces have provided him a rare perspective.
“The top pros on Pickwick and several on the professional circuit today are using knowledge Mr. Long figured out and taught them,” said Clay Coleman, of Clay’s Bait and Tackle, in Tupelo. “He knows what he’s doing, especially when it comes to the technology.”
Long says the first determining factor in what gear someone needs is where they’ll be using it.
“If you only fish in the springtime on the Tenn-Tom Waterway, all you need is 2D sonar,” Long said, “but if you fish the bigger waters like Bay Springs and Pickwick, you’ll want a unit that has the sonar and GPS, the down scan and the side scan. In the deeper places, you need a down scan unit. It uses a much higher frequency in a thin beam that generates an image that lets you see the difference between brush piles and fish. It’s more like a picture. You can see the individual limbs on submerged trees with the down scan.
“The side scan is really nice, but it takes about twice as long to learn how to really read a side scan,” he said. “It scans out of both sides of the underwater transducer, up to 240 feet on each side, but at the maximum scanning distance you can’t really distinguish fish. Most of us run them at 50 to 100 feet on each side, which makes the images bigger. Side scan is very good for finding brush piles, locating ditches and other structure of that nature. It’s good for seeing schools of fish, but with individual fish, they’re so small on the screen it’s hard to see them, but with a little practice you get to where you can see individual fish.”
The precision of the images these two new features deliver let fishermen find structure they otherwise could not have definitively found, and the inclusion of GPS technology in the units allows the recording of waypoints that will lead users back to once-found spots with astounding accuracy.
Long says this gear offers a tremendous body of information to the user but still requires practice, study and experience to reap the maximum benefit. Consideration of the geometry of the area being scanned and the shape of the waves doing the scanning are important in translating where shapes represented on screen actually are in the water. These and similar demands are why Long says you might as well buy the unit with the largest screen you can afford, then spend the time needed to learn to use it.
Wealth of information
Ultimately, though, time spent learning is time spent fishing, which is the whole point in the first place.
“Way back when I started using the electronics, people would look at it and ask, ‘How many fish did that help you catch?’” he said. “The answer is still the same. I don’t know how many I’ve caught that I otherwise wouldn’t have, but I do know it’s made me a better fisherman.”