Largemouth Tech Tips: Water Temp, Fishfinders, Lure Hacks

Largemouth Tech Tips: Water Temp, Fishfinders, Lure Hacks

Begin all your bass fishing with a simple check of your fishfinder’s surface temperature reading. (Photo by Ron Sinfelt)

These three skills belong in your bass-fishing bag of tricks.

Largemouth bass are perhaps the most important freshwater sportfish in North America.

A native or introduced species in 50 states and most Canadian provinces, largemouth will attack a staggering variety of artificial and natural baits and are prized both for their fight and their general willingness to strike.

Recreational and professional bass anglers alike are poised to benefit from recent technological advances in fishing equipment and techniques, innovations that will help them to locate and catch more bass on every trip

Here are three contemporary “tech tips” that belong in your bass fishing bag of tricks.

Take their temperature

Seasonal bass movements in your favorite body of water are driven largely by water temperatures. As bass anglers, if we come to appreciate these temperature-dependent bass movements, we will be able to find and catch more largemouth all year.

Let’s start in the winter. Winter bass in open water are typically found deep, often in 30 feet of water or more, along steep main-lake breaklines where they can be tempted with deep-running crankbaits and suspending jerkbaits. In the northland, anglers will oftenencounter quality largemouth along deep weedlines, targeting them with ultra-finesse presentations or with live bait under tip-ups.

Once waters warm into the 50s, largemouth move toward the shallows to build beds and spawn, a time when crankbaits reign supreme. Males will remain on the beds to guard fry after the spawn — which typically peaks when water temperatures are in the upper 60s to low 70s — while beefy females will vacate the shallows to recover on nearby flats.

In the heat of the summer, the largemouth’s finned forage is frequently driven to deeper, more thermally stable waters, or into weed-choked shallows where vegetation provides shelter from the sun. Bass, of course, will be hot on their heels.

Target summertime suspended bass with cranks or finesse drop-shot rigs, while largemouth in shallow slop respond reliably to topwaters. In the fall, as the water cools from the 70s toward the 50s, bass will again become abundant in relatively shallow water, feasting upon summer’s bounty before winter.

Your fishfinder’s surface temperature reading is the simplest way to determine where your bass fishing adventures should begin on any given trip. If you’re heading out in a canoe or other electronics-free craft, pack a stream temperature thermometer — a favorite of trout-chasing fly-rodders — to measure water temperature.


For anglers who learn to accurately interpret their sonar views, side-scanning technology allows for a better picture of structure and cover (and even fish) that are to one side of the boat. Obviously useful in shallow-water fishing, it’s also handy for covering lots of ground while ‘scouting’ for fish. (Infographic by Ryan Kirby)

Is that a fish?

The marine electronics adorning your boat are perhaps the most powerful and effective tools you own for locating fish. Unfortunately, many anglers harness only a fraction of their electronics’ fish-finding potential. Learning to accurately interpret your sonar unit’s display will provide you with substantial advantages on the water.

In traditional sonar views, fish echoes appear as arches as the fish moves through the sonar’s cone-shaped beam. The size, shape and intensity of these arches are dependent on more than just the size of the fish. Boat speed, the fish’s depth in the water column, and even the sonar cone angle and frequency, can all impact the appearance of these fishy arches.

Fish can also be easily identified in contemporary, high-frequency sonar techniques like Humminbird’s Down Imaging and Side Imaging, methods that probe the water column beneath and off to the sides of the boat to provide easy-to-interpret, picture-like images. Because of their different beam shapes and sonar frequencies, these techniques display fish not as arches but rather as bright spots against a darker background, where the size and brightness of the spot provides direct information about fish size.

Dark sonar shadows that accompany a bright sonar return in side imaging also provide information about the fish’s depth in the water column. Fish that are suspended high in the water column have larger distances between their bright sonar return and the dark shadow than do fish that are closer to the bottom.

What’s the best way to learn to interpret your fishfinder? Time on the water is clearly the best teacher. But if you want to shorten the learning curve, attend a seminar, take a class or spend some quality time with instructional resources from proven sonar aficionados. Being able to take advantage of all of your marine electronics’ capabilities will make you a more efficient and successful angler.

Customize that lure

Commercial bass lures are designed to be effective right out of the package. Nevertheless, it is important to recognize that many lures will work better under specific conditions if we, as anglers, take the time to customize or modify their original profiles, colors or actions.

For example, consider the venerable jig — a lure responsible for innumerable bass catches over the decades since its introduction. Most jigs include a forest of rubber legs that extend well beyond the hook, where they flow and undulate in an enticing manner. When the bite gets tough, and fish start striking short, don’t be afraid to trim those legs back, so that they end right at the bend of the hook.

This will make your jig more compact and help to focus the point of attack at the piercing point of the hook, rather than on the relative safety of the legs. Likewise, take advantage of innovations in modern materials by folding tungsten jigs into your arsenal. Tungsten is a metal that is more dense than traditional lead. This means that a standard 1/2-ounce jighead will be smaller when made of tungsten than when poured from lead.

From the angler’s perspective, a tungsten jig will offer a more compact profile than a lead jig of the same weight, allowing us to fold the traditional principles of finesse fishing into situations that call for jig-and-trailer presentations.

If you’re looking for ways to customize your lures for specific situations, one of the best places to snoop for intel are post-tournament recaps, where victorious anglers frequently describe their winning techniques in detail and with little reservation. Pay close attention to the fine print, where a champion might mention in passing that they added a little lead tape to the belly of their crankbait or swapped out a treble hook for one of a different style or size. These tournament-tested bait hacks can be big difference-makers for you, too.

Get Your Fish On.

Plan your next fishing and boating adventure here.

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