Low-pressure inflatable boats (LBBBs) have become the gold standard for anglers who value comfort and stability on the water, but their design is very different from the classic hard-bottom flat-bottom boats, which dictates their own rules for attachment installation. sounderto get a high-quality picture without damaging the delicate balloon system and retaining the ability to quickly disassemble the boat.
The main difficulty is that the transom of the NDND is often removable or soft, and the sides and bottom are made of PVC fabric, which is subject to deformation under water pressure and equipment weight. Incorrect installation can lead not only to loss of signal or the appearance of “dead zones” on the screen, but also to damage to the boat during movement.
In this article, we'll look at proven installation methods that will help you avoid common mistakes. You'll learn where to place the converter, how to correctly conduct the soft-board cable, and what are the alternatives to the classic transom mount. Lowrance, Garmin or Humminbird It will show a real picture of the underwater world, not artifacts from bubbles.
Choosing the optimal place for installation of the converter
The first thing you need to do before drilling or sticking something is to identify the "work area" on the bottom of your boat. NDND boats are characterized by an inflated bottom with longitudinal or transom partitions (redans), which becomes rigid when filled with water, but remains flexible. The sensor must be in an area where the flow of water is laminar, that is, calm and without swirling.
It's not recommended to put the sensor in the bow or in the middle of the bottom if there are docking seams of cylinders or redans. When you move, the boat hits a wave, and in these places you form cavitation, air bubbles that completely block the sounder signal, in which case the screen will turn into a chaotic set of points, and you will not see any fish or relief. The ideal place is closer to the stern, but with the engine working.
It's important to consider the angle of inclination, and the sensor has to look downwards, perpendicular to the surface of the water, when the boat is moving under load, and because the PVC bottom can bend under the weight of fishermen and cargo, the anchorage point should be chosen on the hardest part, such as on a plywood sleigh, if it reaches the stern, or on a special hard insert.
⚠️ Attention: Never place the sonar sensor in close proximity to the engine's lower unit (less than 15-20 cm). The exhaust gases and flow of water from the propeller will create an insurmountable noise curtain, rendering the sonar useless at speed.
To determine the exact location, many experienced boaters use a time-fixing technique, you can attach the sensor to a suction cup or just tape it to the intended point and make a test swim, which will assess the signal quality and the absence of interference before the final installation.
transom fastening: features for soft translator
The classic way of mounting, on a squirrel board, is the most common, but for NDND boats, it has its nuances. Unlike aluminum boats, where the transom is hard, here we are dealing with an inflatable balloon or a soft board inserted into pockets. A standard bracket with down screws can damage the PVC material or shift during operation.
If your boat design allows, it's best to use a plywood or aluminum hinged transom that is rigidly fixed in the grooves of cylinders, on which solid surface you can attach the sensor through a through hole or on a powerful glue, but if the transom is exceptionally soft (part of the cylinder), you will have to use combined methods.
One of the most effective options is to use a transition plate, a piece of moisture-resistant plywood or plastic that is attached to the soft transom of the boat with wide belts or Velcro straps, spreading the load, and this plate is already mounted on the rod of the sensor, which minimizes the risk of depressurization of the balloon and ensures stability.
When using standard plastic brackets ("floating" or fixed), make sure that the nuts are not pulled. Excessive pressure will lead to the formation of folds on PVC, which over time will turn into cracks. Between the bracket and the fabric must be a gasket of dense rubber or neoprene.
The method "Through the board": tightness and reliability
For those who want to have a sounder permanently installed and don't want to mess with suction cups or removable brackets every time, there's a method of putting the sensor directly into the boat, which requires high accuracy, but provides perfect fluid dynamics and no interference, and is only suitable for experienced users who are confident in their PVC skills.
The method involves cutting a hole in the balloon (usually in the lower part, closer to the keel) and pasting a special embedded element or the sensor itself. Texacoll or KlejcolIt is important to choose the right place so that the surface is smooth with the pumped boat.
The process requires careful surface preparation: stripping, degreasing and applying several layers of glue with drying, the sensor is inserted into the prepared socket and sealed. Once dry, the connection becomes monolithic and can withstand any loads. However, remember that after such a modification, the boat may lose its factory warranty.
Technical nuances of insertion into the cylinder
When you insert a sensor, it's important to consider the thickness of the PVC fabric. It's usually between 0.9 and 1.2 mm. The hole should be strictly in diameter of the working part of the sensor so that there are no gaps. If the sensor is too long, you can neatly shorten it by disassembling the body, but this is a risky operation that violates the tightness of the device itself. It's better to choose a model with a short case specifically for the insert.
There is also the option of placing a "fluid" without breaking the leakproofness of the main cylinder, if the design of the boat has double sides or special pockets for equipment, but for most models of NDNDM this is rare.
Suction fixing and temporary solutions
The most gentle and popular method for PVC boats is the use of powerful suction cups. Modern models of suction cups designed for sonars are able to withstand significant loads and do not damage the surface of PVC. This is ideal for those who like to change the location of fishing or use the same boat for different purposes.
The main advantage of suction cups is mobility, you can easily move the sensor in search of the best signal, which is especially true for boats of complex shapes, and also when you store the boat in a deflated state, the sensor is removed, which prolongs the life of the electronics and the boat itself, because there are no points of constant stress of the material.
But there are some disadvantages to this method: it can come off when you hit a wave or when you're down for a long time, and it has to be perfectly smooth and clean, and it can be difficult to find a flat spot on the ribbed surfaces of the NDNDM, sometimes you have to use transition pads.
☑️ Suction plant inspection
To enhance the effect, some anglers glue a small area of smooth plastic or plexiglass on board, and already attach a suction cup to it, which allows you to install the sensor in any convenient place, regardless of the topography of the balloon, and ensures 100% tightness of the main fabric of the boat.
Cable laying and protection against damage
The right sensor is only half the battle, and the second, equally important, part is the right cable from the sensor to the head unit (display), and the sonar cable is a weak link that often suffers from rubbing, pinching and UV light.
On PVC boats, you can't just throw the cable on the floor, it needs to be fixed along the side or under the sleigh, and plastic cleats are great for mounting, but you need to tighten them without fanaticism, so you don't overrun the inner vein, you better use special clips or Velcro straps.
Pay special attention to the inflection points: at the entrance of the boat and at the connection to the display. Here the cable experiences the greatest mechanical stress. It is recommended to use spring protection or corrugated in these nodes. Also remember the margin of length: the cable should allow you to freely move around the boat without stretching during jerks.
| Type of cable attachment | Pluses | Cons | Recommendation |
|---|---|---|---|
| Plastic clamps | Cheap, reliable, affordable | They can remove isolation over time. | Use with soft pads |
| Velcro straps (Velcro) | Reusable, not scratching. | Wet, pick up dirt. | Good for temporary fixation |
| Silicone sealant | Complete tightness, no holes. | Hard to dismantle, long drying | For fixed inserts only |
| Magnetic holders | Quick installation/dismantling | Requires metallic elements | For boats with metal frame |
Remember, the cable must lie so that you don't accidentally step on it or hit your foot as you move around the boat, and in the tight space of PVC boats, this happens often.
Customization and calibration after installation
After you physically install the sensor, you need to set the head unit up correctly, and even a perfectly mounted sensor will give a bad picture if the sounder parameters are not adapted to the conditions and installation method.
For PVC boats, where the sensor is often close to the surface or has small deviations from the ideal, high frequencies (200 kHz) can produce a lot of noise. Try switching to 50 kHz or using auto-scan mode if your sonar allows it.
Sensitivity and Noise Rejection are also critically important; too high sensitivity will show the engine's porridge, too low will hide the small fish, and find a balance where the bottom is shown in a clear red (or orange) stripe, and the bottom structure is visible in detail.
Use simulation mode to check the settings on the shore. Lift the boat above the water or immerse the sensor in a bucket of water to check the response of the system without risking damage to the sensor on the ground.
Be sure to check the sonar at different speeds. Often, when you're on a riser, it's a great picture, and when you go to plane, the signal goes away, and that's a sure sign of cavitation, and you'll have to move the sensor deeper into the water or change its angle of inclination.
Seasonal storage and maintenance
Operating electronics on water means constant contact with an aggressive environment. Solar ultraviolet, salt water, temperature changes all destroy plastic and insulation. After every fishing trip, especially in salt water, the sensor and cable must be washed with fresh water.
When preparing the boat for winter storage, it is best to dismantle the sensor if possible. If the sensor is built in or glued in, make sure that the cable is not clamped or stretched when the boat is blown away. Stow the boat carefully, trying not to create sharp clamps at the exit of the cable.
Regularly inspect the fastener, the glue may dry out over time, and the screws may weaken from vibration, and a preventive check before the season will save you from losing expensive equipment during the first fishing trip.
The main secret of the longevity of the sonar on the PVC boat is not so much the way of attachment, but regular maintenance and proper storage in the off-season.
Frequently Asked Questions (FAQ)
Can I glue the sensor directly on the inflatable side without a tie?
Yes, you can use special water-resistant PVC adhesives (e.g., polyurethane-based adhesives) to glue the pad or the sensor itself, but this makes dismantling difficult and can leave traces, preferably adhesive-based removable areas or suction cups.
Why does the sonar show "missing" of the bottom at speed?
It's most likely that air (cavitation) gets under the sensor, and this happens if the sensor is set too high, not perpendicular to water, or in the turbulence zone of the boat's structural elements, and try lowering the sensor deeper or moving it to a calmer zone.
Is it bad for the sensor if the boat deflated with it?
There is usually no critical harm unless the sensor has been mechanically damaged (broken, bitten), but constant material stress and possible cable crevices during deflation are undesirable.
Which glue is better to use for sealing the insert?
Best proven two-component polyurethane adhesives (for example, Texacoll 500 hardened Desmodur They provide an elastic, durable seam that holds up to tear and is not afraid of water.
Do I need to lubricate the exit of the cable with a sealant?
Yes, it's a mandatory procedure. Even if the cable fits tightly into the hole, the microslits can expand over time, and using plumbing silicone or a special PVC sealant around the cable will prevent water from entering the balloon.