Finding fish in unfamiliar water or in difficult terrain often turns into a lottery, if you rely only on luck and experience. sonar They've become an indispensable tool for any hydraulic motor, allowing you to see the underwater world in real time right on the screen of the device, but just buying a device is not enough, you need to understand the physics of ultrasound propagation and be able to interpret the resulting picture.
In this article, we will take a look at all aspects of sonar operation, from the initial installation to the finer points of setting up for different fishing conditions, learn to distinguish between driftwood and fish, understand the structure of the bottom and choose the best scanning parameters, and focus on practical tips that usually come with years of practice, but are now available immediately.
No matter what your budget is. Lowrance professional GarminThe basics of the work remain the same. It only takes a few minutes to set up properly, but it saves hours of fruitless waiting for cool stuff. Let's figure out how to turn your gadget into a real water assistant.
The principle of operation of sonar and types of emitters
The basis of any sound sounder is a transducer that generates sound waves and receives their reflection. The signal travels in water at a speed of about 1,500 meters per second, and the device calculates the distance to the object by measuring the time of return of the echo. The higher the frequency of the signal, the more detailed the picture, but the less depth of penetration. Boat Fishing is most often used frequencies. 83 kHz and 200 kHz.
Modern models are equipped with technology CHIRP Comppressed High-Intensity Radar Pulse, which emits a continuous signal over a wide range of frequencies, allows for much better target separation and image clarity at greater depths. Unlike traditional sonars, CHIRP emitters do not go blind when passing through thermoclines and better display small fish.
⚠️ Attention: When installing the sensor, make sure that the front part of the emitter is pointed strictly along the boat's path. The wrong angle of installation will cause noise and loss of signal at speed.
It's important to understand the difference between the cone of radiation and the actual coverage. 60 degrees. It doesn't mean you see fish right under the boat; at 10 meters down, the cone's diameter is more than 10 meters. The fish on the edge of the screen can be a few meters away.
Why does the sonar show emptiness?
Fishers often see holes in the bottom or a void, which may be because dense vegetation or soft mud absorbs the signal without reflecting it back, and it may be because the boat is moving too fast, causing the sensor to not process the reflected signal.
Installation and initial setup of equipment
The quality of the image depends on the correct installation of the sensor. For PVC inflatable boats and aluminum boats, there are different types of attachments: transom, off-board and cut-in. The main requirement is that there are no air bubbles between the working surface of the sensor and the water, since ultrasound does not pass through the air.
The initial setting of the device menu should be done before getting on the water. Select the language, units of measurement (meters or feet) and the type of sensor installed.Auto) is suitable for most situations, but for detailed study of the bottom it is better to use manual settings of feelings
☑️ Pre-launch checks
When you move a boat, it's important to consider cavitation, which is the formation of air bubbles around the sensor because of turbulence, and if you have vertical white stripes on the screen or the image becomes intermittent, then the sensor is too high or has the wrong angle of attack, in which case you need to lower it below or change the angle of inclination.
| Parameter | Description | Recommendation |
|---|---|---|
| Frequency | Signal range | 200 kHz for depth, 83 kHz for review |
| Range (Range) | Depth of scanning | Automatic or 20% reserved |
| Sensitivity | The power of echo reception | 75-85% for a clear picture |
| ASP (Noise Reduction) | Impediment filter | Only in case of severe ripples |
Interpretation of the image on the screen
The hardest step for a beginner is learning to read the screen, the bottom is shown by the widest and brightest stripe at the bottom of the display, the hard bottom (stone, shell) gives a powerful reflected signal and a wide band, while the soft bottom (silt, sand) reflects the signal weaker, and the stripe will be thinner. Double echo of the bottom often indicates the presence of a thermocline or a very hard surface.
The fish is shown as arcs. The size and shape of the arc depends on how long the fish has been in the cone of the emitter. The large arc means that the fish has swam through the center of the cone, the small one has gone along the edge. If you see just vertical bars on the screen, it's probably a small fish joint or a flock of fry in the water column.
- 🐟 Single arcs: Large predatory fish (pike, perch, perch), which is kept at the bottom or in the waters.
- 🌫️ Point clouds: Small fish, plankton or slurry in water, often attracting predators.
- 🌿 Vertical pillars from the bottom: Aquatic vegetation, the height of which is determined by the separation of the signal from the main line of the bottom.
For a detailed study of the structure of the bottom, use the function Zoom It allows you to stretch the area of the bottom layer to see if the fish is standing directly above the bottom or pressed against it. White Line (white line), which color the strongest reflections white, helping to distinguish fish from algae.
Use the Split Frequency feature if your sonar supports 2D mode, which allows you to see a picture on one screen at low frequency (broad view) and high frequency (detail), which helps you identify objects faster.
Sensitivity adjustment and noise suppression
Factory sensitivity settings are often too aggressive, resulting in excess "garbage" on the screen. Excess sensitivity causes the sonar to respond to the suspension in the water and thermocline, creating chaotic spots. Optimal adjustment is achieved experimentally: reduce sensitivity until the fine details of the bottom begin to disappear, and then add 5-10%.
Noise reduction function (Noise Rejection or ASP) It's useful in excitement, when the sensor is constantly changing the angle of immersion. However, in calm water, it's better to turn it off or minimize it, because with noise it can cut weak signals from fish. Remember that the sounder shows not the fish itself, but the swim bladder, so the size of the arch depends on the volume of gas inside the fish.
⚠️ Attention: Don't blindly rely on automatic fish IDs (fish symbols). They often mistake floating bubbles or bundles of grass for fish. Always analyze the raw signal (arcs and colors).
For deep-sea fishing, for example, when fishing at depths of more than 10-15 meters, sensitivity can be increased, but be sure to turn on the filter of surface interference (see below).Surface ClutterThis will remove the porridge in the upper layers of water caused by ripples and allow you to focus on the bottom space where the predator is standing.
Finding fish in different types of water
The sounder tactics on the river and on the lake vary significantly. On rivers with strong currents, fish often stand in pockets behind obstacles (rocks, snags, fallen trees), where the current is weaker. The sounder helps to find these relief anomalies. On lakes, fish are more often tied to eyebrows, dumps and underwater banks, which are also easily detected by changes in depth.
When you catch pike, look at the grass thickets. The sounder clearly shows the top of the vegetation. If you see gaps in the grass line or "windows" among the thickets, these are ideal places to throw. Perch and perch often stay at the border of pure water and vegetation, controlling the movement of small things.
Winter echoer fishing requires a special approach. In ice conditions, the signal is better because there is no wind surge. However, accuracy in displaying small movements is critical.Fast Update) to see the game and the fish's reaction to it in real time.
- 🏞️ Rivers: Look for the depth differences, the reverse flow and the boundaries of the jets.
- 🏝️ Lakes: Scan the eyebrows, underwater elevations and the edges of the dump.
- 🌊 Reservoirs: Old riverbeds and flooded trees.
Typical mistakes and expert advice
One of the most common mistakes is to move at too high speed. At speeds above 10-15 km/h (depending on the model), the sensor can start to catch air, and the picture disappears. For detailed terrain scanning, move at a speed of 3-5 km/h. This will allow the device to update the picture enough times to build a clear image.
Many anglers ignore battery power. Echo sounders, especially those with bright screens and active sonar, consume significant current. A sudden blackout in the middle of a fishing trip is an unpleasant surprise. Always have a supply of energy or connect the device through a charge control system.
The main secret of successful use of the sonar is not to constantly look at the screen, but periodically glance, remembering key relief points, and then fish, trusting your experience and memory, checking with the device if necessary.
And remember to calibrate the speed of sound if you're fishing in salt water or if you're fishing in a very high temperature, the speed of sound in salt water is higher than in fresh water, and without correction, the depth readings can be distorted by a few percent, which at great depths will give you a significant margin of error.
How to distinguish a snag from a fish on the screen?
The snag on the bottom usually gives a stable, powerful signal that does not change its position relative to the bottom when the boat passes back and forth. The fish will always shift. In addition, the snag often carries a "leaf" of interference upstream, and the fish is displayed in a clear arc.
Why does the sonar show the fish and the hook is empty?
It can be small fish that are not interested in bait, or fish that are out of sight of your gear (above or below the hook), and the sonar can also mistake large air bubbles or dense clumps of algae that pop up from the bottom.
Do I need an expensive GPS sonar for a beginner?
To start with, a budget model without a cartplotter is enough, and the main task is to learn to see fish and terrain. GPS navigation and building depth maps are the next level of functions that you'll need when you want to remember catchy dots and return to them with a meter accuracy.