Modern fishing from a boat is unthinkable without an electronic assistant that can look under the water. echoer It turns the invisible underwater world into a graphical image that allows the angler to make informed decisions about where to throw the gear, but the mere fact of having a device on board does not guarantee catch if the user does not know how to correctly interpret the data that is displayed on the screen.
Many newcomers make the mistake of relying solely on automatic settings or believing that the device will show them the exact fish with the species name. sounder It's a complex sonar radar that depends on a variety of factors, from the speed of the boat to the chemistry of the water, and understanding the physical principles of sonar is key to successfully using the device in real-world conditions.
In this article, we'll look at all aspects of sonar operation, from initial installation and calibration to the subtleties of reading the bottom relief and the algae fish, and learn how to adjust sensitivity, choose the right scanning frequency, and most importantly, understand what's going on under your keel at this moment, and that knowledge will transform you from a passive observer into an active strategist on the water.
Principle of operation and basic controls
The basis of any sonar is a simple physical principle of echolocation. transducer And when you see obstacles, whether it's soil, a snag, or a fish joint, it bounces back and returns to the sensor, which converts it into an electrical signal.
The processor calculates the time of the signal and displays the result on the screen as a graphical image, and it is important to understand that the picture on the display is not a static photo, but a continuously updated history tape, where the left displays older data, and the right — the current moment. Scanning speed The screen depends on the speed of your boat.
The control of the device is done through a menu, which can be touch-sensitive or button-based. The main parameters that you will have to work with constantly include: Gain (magnification/sensitivity), Range And you don't have to be afraid to experiment with these settings, because there's no universal recipe for all water bodies.
⚠️ Warning: Never turn on the sonar without a submerged transducer. The operation of the emitter "dry" even for a few seconds can lead to overheating of the crystal and irreversible failure of the device.
Why does sound travel through water and not through air?
Sound waves are not transmitted well from the air to the water because of the density difference, so the transducer must be strictly underwater, and there should be no air bubbles between it and the boat hull that shield the signal.
Installation of equipment and preparation for the first launch
The quality of the image on the sonar screen 80% depends on the correct installation transducerFor PVC boats and small metal vessels, the most common option is to attach to a transom panel, and the sensor must be installed so that its working surface is parallel to the surface of the water when the boat is moving at working speed.
The horizontal position of the emitter is critical to getting a clear signal. If the nose of the sensor is upwards, the sonar will catch air bubbles and show chaotic interference. If it is too lowered to the water, resistance and risk of impact on the obstacle will increase. The optimal depth of immersion of the lower edge of the sensor is 3-5 cm below the bottom of the boat.
Electrical connection also requires care. Use only regular cables or quality analogues with a cross-section of at least 1.5 mm2 to avoid voltage drops over long distances. All connections should be securely insulated, as fresh and especially salt water is an aggressive medium for contacts.
☑️ Pre-launch checks
After physical installation, you need to perform the initial setting of the language, units of measurement (meters or feet) and the type of boat in the instrument menu. Lowrance or Garmin This allows you to choose the type of body, which helps the algorithms of noise filtering better adapt to the conditions of navigation.
Frequency and sensitivity settings for different conditions
One of the most important parameters that influence the detail of the picture is the frequency of radiation. Most of today's dual-frequency sensors operate in the 83 kHz and 200 kHz bands. Low frequency. (83 kHz) provides a wide viewing angle and greater depth of penetration, but gives a less detailed image, ideal for quick fish search at greater depths or when trolling.
High frequency 200 kHz, by contrast, has a narrow beam, but it shows the smallest detail of the bottom relief and allows you to distinguish between individual fish bladders. When you get to a perspective point and anchor or slowly drift, switching to a high frequency will help you see the structure of the bottom literally in centimeters. Some advanced systems use CHIRP technology, which scans a wide range of frequencies at the same time.
Sensitivity parameter (S)Gain Sensitivity regulates the sonar's ability to see faint reflections, too sensitive will cause "snow" and noise on the screen, hiding the useful signal, too low will make the instrument "blind", and it will stop seeing small fish or soft bottom.
The optimal sensitivity setting is done by sampling. Increase the value until there is noise on the screen, and then reduce it a little. In murky water or when there is a heavy chop, sensitivity will have to be reduced to cut off surface interference.
Reading an echogram: how to distinguish fish from the bottom and algae
The most difficult skill for a beginner is to interpret what he sees on the screen. Bottom This line is usually shown by the widest and brightest strip at the bottom of the screen, and the thickness of this line depends on the hardness of the soil: the rocky bottom gives a greasy, wide arc, and the soft silt gives a thin line. Often you see the "second bottom" - a weak repeat of the contour of the bottom below the main one, which indicates the hardness of the soil.
Fish The sounder is most often seen as an arc, and this arc is created because the fish enters the cone of the beam, passes through the center of the beam, and exits it. If the boat is standing still, the fish will look like a vertical strip that moves up and down with the water wobble, and the shoals of small fish will appear as a cloud of small dots or strokes.
Algae Thermoclines look different, and vegetation is usually seen as blurry, fuzzy patches hanging from the surface or growing from the bottom, but without a clear arc-like structure. thermoclin (the boundary of water layers of different temperatures) may look like a false bottom in the middle of the water column, but when the depth of the sonar changes, this line will disappear or shift.
| Object | Appearance on screen | specifications | Actions of the fisherman |
|---|---|---|---|
| Hard bottom. | Fat, wide line | There is a second echo, clear boundaries. | Bottom-fishing |
| Soft silt | Thin, pale line | No second echo, signal fades | Use lightweight tools |
| Single fish | Clear arc | Changes size when passing through the center of the beam | Point-point or drift |
| Gas bubbles | Vertical columns | Start from the bottom and go up. | Ignoring, it's not a fish. |
⚠️ Warning: Don't confuse driftwood with fish. Snags are static, often angular, and "grow" from the bottom. Fish are always above the bottom and tend to move relative to the boat.
Fish search and bottom structure analysis
Effective use of the sonar means not just looking at the screen, but actively searching. When you move on a boat in a zigzag or parallel galley, you create a map of the terrain. Look for anomalies: eyebrows, dumps, pits, free-standing stones. Bottom relief It often dictates to the angler where the predator is, Pike likes to stand in the grass or at the edge of the dump, the pike prefers hard spots at depth, and the perch is kept in flocks above the depths.
If you see a fish on the screen, don't be too quick to drop anchor. First, you should look at the density of the fish and the reaction of the fish to the boat. If the fish runs away (arcs go abruptly to the sides or down), then it's scared of the noise of the motor, in which case you should step back and throw the gear from a distance or use an electric motor.
Use the function Zoom And so, if you zoom in, you can actually zoom in and see the area of the bottom where you see the activity, and you can actually stretch the image vertically and see exactly how high the fish are from the bottom, and that's critical for the bait wiring horizon.
Use the Trackback feature: If you saw a fish on the screen but didn't get to the point, stop the boat and scroll back to pinpoint the coordinates of the catch.
Remember, the sonar shows what's directly underneath the sensor, and if you're anchored and the fish are cruising around the boat, you can only see the blank screen until it comes under the keel, so lightly rocking the boat or short movements can help to hook the fish with the beam.
Typical errors and ways to fix them
Even experienced anglers sometimes have problems with echolocation. One of the most common mistakes is to misset the speed of the screen. If the speed is too high, the fish arcs will look like straight lines, and it will be impossible to determine the presence of fish. If it is too low, the picture will swim. Adjust this parameter to your current speed.
Another common problem is the loss of the bottom at great depths or in overgrown places, often solved by manually setting the range (see below).Range) instead of automatic mode: Forcedly limit the depth range (e.g., 0 to 10 meters if you are fishing in shallow water), and the sonar will scan this layer with maximum detail and frequency of updates.
And remember, the impact of the boat speed is that at high speeds (over 10-15 km/h), cavitation bubbles can form under the sensor, which completely block the signal, and then you'll see a white band (the blind spot) just below the surface, and the solution is one: slow down or shut down the sensor.
⚠️ Warning: Don't blindly rely on fish symbols that draw some budget sounders. The algorithm can mistake a fish for a bunch of grass or a stone. Always rate the primary echogram (raw data), not just graphic symbols.
The secret to success is to practice and compare the readings of the instrument with real fishing, and only experience will allow you to instantly recognize the nuances of the underwater world.
Can I use the echo sounder in winter from the ice?
Yes, you can, but it requires a special mode of operation or a separate winter sensor, a conventional transducer must be pressed to the bottom of the hole through a layer of water or use a special stand. The ice does not let ultrasound through, so the sensor should not touch the ice directly, unless it is a specialized winter model.
Why does the sonar show the fish and the cool one doesn't?
You might not see fish, but a thermocline, methane bubbles from the bottom, or a cluster of plankton, and fish may be passive and not respond to bait, even if it's present at the point. Try changing the fishing horizon or the type of bait.
Is the sonar bad for fish?
No, the radiation output of household sonars is negligible and absolutely safe for aquatic life, and the frequencies used in sonars do not harm the hearing or health of fish, unlike industrial sonars.
How to extend the life of a sonar battery?
Use deep discharge batteries (GEL or AGM) to power the sonar. Do not leave the device connected to the battery for a long time unattended, as even when turned off, some models consume current to save settings or work the GPS tracker.