Successful fishing from a boat has long ceased to be a guessing game, where the outcome depended solely on the luck and intuition of the angler. With the advent of affordable and reliable sonar, every boater was able to look under the water without dipping his head into the off-shore water. But the presence of a modern gadget on board does not guarantee catch unless he can read the information correctly from the screen.
Many newcomers make the same mistake: they buy expensive equipment, they put it on a transom, but they rely on basic factory settings, which leads to the device showing only the bottom relief, passing schools of fish or giving false signals from the thermocline. Correct interpretation of data It requires an understanding of the physics of sound waves propagation in water and the specifics of the specific sensor.
In this article, we'll take a look at the finer points of sounder tuning, learn how to distinguish fish from bottom vegetation, and learn how to change your search tactics depending on the time of day and season. Using sounder wisely turns chaotic wandering around a body of water into a focused search for promising points.
Principle of operation and types of sensors for boat fishing
The basic physics behind any sound sound sounder is that it sends down a sound pulse that bounces off obstacles and comes back, and the timing of the signal's return and its strength allow the processor to build a picture. ray-cone It is not a laser beam, but rather light from a flashlight that expands with depth.
There are several basic types of sensors, and choosing between them is critical to effective search. Classic single-beam models are a thing of the past, giving way to two- and three-beam systems, as well as CHIRP technologies. The latter allow scanning a wide range of frequencies, providing high resolution images even at great depths.
The frequency of radiation directly affects the detail and coverage. High frequencies (e.g. 200 kHz and above) give a clear picture, but have a narrow cone, which is ideal for detailed study of the bottom under the boat. Low frequencies (50 kHz) penetrate great depths and have a wide angle of view, but with less resolution.
CHIRP technology against conventional frequencies
CHIRP (Compressed High Intensity Radar Pulse) sends a continuous frequency-changing signal, allowing for the separation of targets that are very close together, while a conventional sonar can merge them into a single pile.
When choosing equipment, you should pay attention to the power of the emitter and the sensitivity of the receiver. A weak signal simply will not penetrate the layer of the thermocline or dense algal vegetation, and the fish will go unnoticed. Garmin, Lowrance and Humminbird There are different solutions, but the principle remains the same for all.
Proper installation and initial setting of the device
Even the most expensive sonar will be useless if the sensor is installed incorrectly, the main task is to ensure a stable flow of water to the emitter and minimize vortices. When mounted on the transom of a boat, it is important that the sensor is immersed in water even when moving on the plane, but does not create unnecessary resistance.
After the physical mounting, you have to calibrate, and the first step is always to choose the language, the units (metres or feet) and the type of boat, and many people forget to specify the type of hull, which leads to errors in determining the speed of sound and, as a result, depth.
- 🛶 Select the type of installation: transom sensor, sensor in the case or thrown.
- 🌊 Set the correct sound speed for your body of water (fresh or salt water).
- 🔇 Turn off the automatic mode if you plan to learn to read the echogram manually.
Sensitivity is a critical parameter, and in automatic mode, the device often strangles weak signals to clear the screen of noise, but small fish disappear as well. Manual setting It allows you to add (gain) to see the details that the automation hides.
☑️ Primary sounder setting
For beginners, linear schemes are often recommended, where the intensity of the color depends on the strength of the reflected signal. More experienced users can switch to custom palettes to highlight certain bottom structures or types of fish.
Interpretation of the echogram: how to distinguish fish from garbage
The most common question for beginners is how to figure out what's underneath the boat. On the sonar screen, fish are most often shown as arcs, and that's because the fish enters the cone of radiation, passes through the center of it (maximum signal strength) and exits it, and if the boat is standing still and the fish swims, there will be no arcs, there will be vertical stripes.
But not all arcs mean trophy. Bottom vegetation, snags, and even gas bubbles can give similar signals. The key difference between fish is that the signal is clearly bound and moved relative to the bottom. Vegetation is usually tied to the bottom and has more blurred, torn edges.
| Object on screen | Appearance | Conduct | Probability of fish |
|---|---|---|---|
| Single arc | A clear arc torn from the bottom | Slowly shifting. | Tall (large fish) |
| vertical | Straight line up and down | Standing still or shaking | Middle (fish under the boat) |
| Cloud of points | Small intermittent dots | Moves with the tide | Low (plankton or debris) |
| Hard signal. | Bright wide stripe at the bottom | Immmovable. | Low (stone or driftwood) |
Pay attention to the dead zone just below the sensor, and because of the time it takes to switch from transmission to reception, it doesn't see objects in the top water immediately below it. A large predator can stand 1-2 meters under the boat, but the sonar will not show it unless you use real-time mode with minimal delay.
Finding fish depending on the time of year and day
Sound sonar tactics change dramatically depending on the seasons: in the spring, when the water is still cold, the fish is sluggish and rests in warmed shallow waters. At this time, the sonar can show fish pressed tightly to the bottom or to the walls of pits. High frequencies are not always justified here, because you need to see the overall picture of the bottom relief.
In the summer, things change. You get a thermocline, a water layer with a sharp temperature difference, and there's little oxygen below that, and there's no fish living there. The sonar shows the thermocline as a horizontal band that can mask fish. It is important to adjust the sensitivity so that objects above and below this layer can be seen, if the instrument permits.
At night and dawn, fish often go out to watering and browsing, during which time the sonar becomes indispensable for finding individual sites, and during the day, especially in the heat, the fish can go to the depths or hide in the shadow of underwater objects, which the sonar identifies as anomalies of bottom relief.
⚠️ Attention: During spawning, fish can react aggressively to sonar signals, especially at low frequencies. If you notice that the arcs break sharply from place when passing a boat, try reducing the radiation power or changing the frequency.
Use of echo sounder for different types of fish
Other fish species behave differently, and the sonar helps to adapt the fishing strategy. The pike is often ambushed at the boundaries of vegetation or the snag. On screen, it looks like breaks in a solid bottom line or vertical structures with arcs next to it, and the sudak prefers to keep flocks at deep brows, and finding it requires careful scanning of the dump.
White fish (bream, roach) often form huge clouds in the water column. Beginners may think this is a disturbance, but an experienced angler will see the structure. If you see large single arcs above such a cloud, then the predator has already gone hunting. This is the perfect moment for a spinning throw.
- 🎣 For pike, look for sharp changes in depths and vertical objects.
- 🐟 For pike, scan deep-sea plateaus and dumps into pits.
- 🦐 For perch are characterized by "boilers" in the halves, visible as moving masses of points.
When catching catfish, deep pits and pools are important. The sonar will help you find the entrance to and exit from the pit, where this predator most often stands. The catfish can lie still on the bottom, merging with the relief, so it is important to look at the color of the signal - the catfish will give a more powerful and wide response than a regular stone.
Use zoom on the bottom layer to see in detail whether the fish is lying on the bottom or just the relief, zooming in allows you to see even small movements of the tail.
Common Mistakes and How to Avoid Them
One of the most common mistakes is blind faith in automatic mode. Automation is good for a quick start, but it often fails in difficult conditions, for example, it can take a thermocline at the bottom or ignore a weak fish, considering it noise.
The second mistake is ignoring the speed of the boat. To map the arc correctly, the speed must be optimal. Too fast a passage will prevent the processor from drawing a full arc, and the fish will look like a comma or a dash. Too slow a passage blurs the picture.
⚠️ Warning: Never rely on a sonar alone when maneuvering in unfamiliar places. Electronics may not see a thin snag or net that can damage the screw or the sensor itself. Always have visual control.
Fishers also often forget to update their device's software, manufacturers regularly release firmware that improves signal processing algorithms and fixes bugs, and checking the current version of the software is part of the boat's electronics service culture.
The main secret of success is not the sounder model, but the ability of the angler to understand what he sees on the screen, and the ability to quickly reconfigure the device under changing conditions.
FAQ: Frequently asked questions
Does the sounder show the name of the fish?
No, conventional sonars are not biological analyzers; they show the presence of an object, its size and depth. Some advanced AI models may assume a type of fish (e.g., Big Shark bass), but this is only a probabilistic estimate of the algorithm based on size and behavior, not an accurate diagnosis.
Can you see the fish on the side of the boat?
The standard transom sensor scans water only under the boat (down). To see fish on the sides (left and right), you need a side-imaging sonar or a separate side-imaging sensor. A normal 2D sonar cannot see the sides.
Why does the sonar show a fish but the hook is empty?
You may not see fish, but you see bottom debris, gas bubbles, or thermocline, and the fish may be very shallow for your bait, or it may be in a passive state and not responding to the stimulus, and sometimes the sonar shows the fish above the bottom, and you drag the bait down the bottom.
Do you need a boat for winter fishing?
Yes, in winter, especially when fishing at great depths or during periods of squeeziness, the sonar is critical. It helps to find wintering pits and fish clusters that do not move actively, but in winter it is important to use sensors that work at low temperatures, because batteries and screens can behave differently.