Fishing with PVC boats is very different from fishing from shore or stationary structures. The presence of an outboard motor gives mobility, allowing you to quickly catch promising points, but at the same time creates serious interference with the electronics. echoer In these conditions, it becomes not just a toy, but a basic navigational tool that allows you to see the topography of the bottom and the accumulation of fish in real time, but the vibrations generated by the engine and the electric tips can turn the screen into a porridge of noise, if you do not approach the issue of equipment competently.
The main difficulty is that squirrel-boat They don't have a hard keel, like metal boats, and they're subject to a lot of rolling. A sensor that's not fixed properly will dive and then fly out of the water, interrupting the signal. Also, at low speeds and when the engine is running at idle speeds, there's often a cavitation effect, where the air bubbles completely block the ultrasonic signal. Understanding the physics of the process and the right equipment is the key to successful fishing, not just having an expensive gadget in your backpack.
In this article, we will discuss the technical nuances of choosing a sonar specifically for small-sized boats with outboard motors. You will learn why scanning frequency is more important than power in shallow water, how to organize power without the risk of discharging the battery to zero and what tricks are there to install the sensor to minimize the impact of the screw. For PVC boats, it is critical that the weight of the entire set does not exceed 10-15% of the load capacity of the cylinders, otherwise the handling of the vessel on the water will deteriorate. This is the foundation on which all further adjustment is built.
Criteria for the selection of sonar for small craft
When selecting the instrument flyboat You don't need a huge display that takes up half the cockpit, or a super-powerful emitter that punches a hundred meters of depth -- that's redundant on rivers and lakes -- and compact models with a 4 to 7-inch screen that are easy to fix on a removable bracket and quickly remove after fishing are the best solution.
Special attention should be paid to the type of emitter. double-frequency Or modern scanning technologies like DownVision and SideVision, which not only allow you to see the depth below you, but also to see the structure of the bottom on the sides of the course, which is critical when looking for brows and dumps. A single beam of 200 kHz will only give a dry digit of the depth, but will not show the fish standing away from the boat.
Protecting the body from moisture and impact is another key parameter. Standard IPX7 It's the minimum, but it's better to look for models with a higher Protection rating, because engine spray and rain are constant satellites of the water element. The plastic of the body must be frost-resistant and resistant to ultraviolet light, otherwise, after the season of operation in the bright sun, it will begin to crumble.
Don't chase brands if you're a beginner. Often budget models of Chinese manufacturers, such as Lowrance entry-level Garmin The Striker series, which is as good at handling inland waters as the flagships, is designed to have a clear menu and manual sensitivity adjustment, as automatic modes often fail in high-swelling or grassy environments.
Nutrition and protection from interference
The PVC powered boat is a high-risk area. The outboard generator (if any) and the ignition system create powerful electromagnetic fields that are induced on the sounder's power wires, creating characteristic stripes on the screen. To avoid this, you only need to use a high-quality cable with shielding and be sure to install a fuse in the break of the plus wire.
For feeding the sonar is best to use a separate tractor Connection directly to the engine terminals is strictly prohibited, since power surges at engine start can burn the electronics of the device. The optimal solution is to use LiFePO4 batteries that are lighter than lead analogues and are not afraid of deep discharge.
⚠️ Attention: Never use power wires longer than 3-4 meters without increasing their cross-section. Elongation of the cable leads to a drop in the voltage at the input of the device, which causes it to spontaneously turn off or malfunction.
If you see a lot of interference on the screen, try changing the wire tracing. Laying the power cable parallel to the motor wiring harness or along the side where other electrical circuits pass is guaranteed to create a background. It is also worth checking the reliability of the "mass" - poor contact of the negative wire is often the cause of the work device instability.
To combat high-frequency interference, put a ferrite ring on the sounder power cable as close as possible to the connection connector, a cheap and effective solution.
Installation of the sensor: transom or cast-off version
The choice of the way the sensor is attached determines 90% of the success of the whole venture. For PVC boats with a motor, there are two main ways: attachment to a transom or using a throw float. The trunk mount gives a stable picture on the go, but requires drilling the cylinder or the use of special suction cups / suction cups, which is not always reliable with active planing.
The drop-down sensor on the cable is a popular but compromise solution. Float-transducer It's easy to lose, it blows away by the wind, and it creates additional resistance to water, but for quiet fishing in calm or using an electric motor, this option is quite viable, the main thing is to fix the cable so that it does not fall under the screw of the running motor.
There is also the option of mounting the sensor on a remote bracket, which is mounted on the balloon using belts or suction cups, which allows you to place the emitter in an area free of air bubbles coming from the bottom of the boat, and it is important that the working surface of the sensor is strictly parallel to the surface of the water when the boat is in motion.
☑️ Verification of sensor installation
If you choose a stationary mount, make sure that the sensor is not in the "kilvater jet" zone from the bottom of the boat. Air bubbles that break off PVC irregularities create a "dead zone" in which the sonar becomes blind. Shifting the sensor closer to the nose or using an elongated bracket solves this problem.
Setup of the device for different fishing conditions
After installation, the fine-tuning stage begins, factory presets are often not suitable for specific conditions.SensitivityToo high will add a lot of debris and noise, and too low will not show small fish, it is optimal to set the automatic mode, but be able to quickly manually adjust.
The important parameter is the speed of the screen scroll (Chart SpeedAt high speed, the speed of the boat's movement should be increased so that the image does not stretch and objects do not merge into a solid line. For parking or slow trolling, the speed is reduced to study the structure of the bottom in detail.
Use of the function Zoom (approximation) allows you to look at the bottom layer, where fish are most often standing, and splitting the screen into multiple windows (Split Screen) allows you to see the big picture and the magnified fragment simultaneously, and this is especially useful when looking for specific objects in known terrain.
| Parameter | Parking/trolling | For a quick ride | For shallow water |
|---|---|---|---|
| Frequency | High (200 kHz+) | Medium/High | High (detailed) |
| Sensitivity | 70-80% | 60-70% | 50-60% (remove noise) |
| Depth range | Automatic. | Fixed | Minimum (0-10m) |
| Color palette | Contrast | Bright | Black and white (clearness) |
Don't forget to set the thresholds to separate the fish from the bottom, and in shallow water, the sonar can confuse the fish lying on the bottom with the bottom itself, and adjusting these values allows you to cut off the bottom and see objects that are a few centimeters away.
Combating cavitation and propeller noise
One of the major problems with motorboat sonars is cavitation, which is the process of vaporization, where the pressure drop creates bubbles that completely reflect the ultrasonic signal, and the screen is then covered by chaotic dots, and the instrument stops "seeing" the bottom, most often when you're dialing speed or gleaming.
To minimize the effect, try to position the sensor as far away as possible from the rotor projection. If the sensor is transom, lower it below the bottom line, but make sure that when it rolls, it does not come out. CHIRP It also helps, as they filter noise better than older single-frequency models.
⚠️ Attention: If you move against the wave, the sensor starts to come up, slow down. The transducer's airborne operation (even short-term) is not dangerous for modern devices, but data will be lost, and mechanical damage to the water on entry is possible.
It's also worth checking the surface of the sensor itself, and the algae, dirt, or scratches on the emitter distort the signal and promote bubble formation, and cleaning the working surface with soft cloth after each fishing trip will prolong the life of the device and improve the quality of the image.
What if the sounder shows "porridge" on the move?
This is a classic sign of cavitation or interference, and try lowering the sensor deeper, changing its angle of inclination, or moving it away from the center axis of the boat, and also check if the power wire passes next to the engine ignition coil.
Seasonal storage and maintenance
Electronics in the water are aggressive. Salt water, temperature changes and humidity require special care. After every fishing, especially in salt water, you need to wipe the body and screen with a damp (fresh) cloth. Salt, drying, crystallizes and can damage buttons or penetrate the seals.
Store the sonar and battery in winter should only be in a warm, dry room. Lithium batteries You can't leave the cold charged less than 50-60%, and the lead is better to keep on recharging. The device itself is also better to heat, because the plastic in the cold becomes brittle, and an accidental impact can split the case.
Check the status of the contacts and connectors regularly. Contact oxidation is a common cause of failure. Use a special lubricant for electrical contacts (for example, silicone-based) to protect the connections from moisture. Remember to update the device software if the manufacturer releases new versions that improve signal processing algorithms.
Proper off-season storage and regular cleaning of salt deposits prolong the life of the sonar 2-3 times, maintaining the clarity of the image for many years.
Can I use a sonar in winter when the boat is in the cold?
You can use the device at low temperatures if the specification permits it (usually down to -10°C). However, you can't dramatically apply the cold appliance to a warm room, because it creates condensation inside, which will disable the electronics. Let it warm up when it's off for a few hours.
Why does the sounder show two arcs (double bottom)?
This phenomenon is called secondary echoes, and it occurs on a hard bottom (stone, silt) when it's sensitive, and it bounces off the bottom, then off the surface of the water, and back off the bottom, and to remove this porridge, you need to reduce sensitivity, or turn on the secondary echo suppression function, if you have one on the menu.
How to distinguish fish from snags on the screen?
The fish is usually shown as an arc, as it swims through the cone of the beam: the distance to it decreases and then increases. A static object lying on the bottom (snag, stone) will look like a solid line or spot. There will be no arc when passing over the snag, unless the fish is above it.
Do you need GPS in the PVC sonar boat?
For motor fishing, yes, for sure. GPS allows you to put waypoints on catchy spots, return to them on the track and control the speed of movement (which is critical for trolling). Without GPS, you lose navigational anchorage and the ability to repeat a successful route.