Choosing a swimming aid for a serious angler or waterwalker often comes down to finding the perfect balance between load capacity, weight and comfort. NDMAIt is the size of 390 centimeters (or 3.9 meters) that is considered the golden mean for two or three people, allowing you to confidently go out into large water even in the presence of a small wave.
Such a boat is not just an inflatable toy, but a full-fledged one. water-motor complexThe design of the 390 is very different from the rigid floorboard bottom models, providing unique build and safety advantages. As you understand the nuances of this model, it is important to understand that you are not just getting an inflator, but a complex engineering product that requires the right approach to operation.
In this article, we will take a look at all aspects of owning a 390 cm inflatable floor boat, from the choice of materials and design to the intricacies of tuning and repair. You will learn why many experienced water engines are switching to NDNDM, and whether you should do it. This information will be useful for both beginners planning their first purchase and owners who want to optimize the use of their vessel.
Design features and structure of the bottom of the NDND
The main distinguishing feature of the model is, of course, the system of bottom formation. Unlike classical boats, where the rigidity is provided by aluminum or plywood sheets (floorboards), here this function is taken over by the shell itself from dense PVC. The bottom is a separate cylinder that is pumped to the working pressure, usually 0.2-0.25 atmosphere. floor provides the necessary rigidity of the structure in the assembled form.
Inside the bottom cylinder, there's a system of special strut belts, known as "lee cables," which connect the top and bottom of the shell and keep the balloon from swelling into a balloon when pressure increases, which keeps the bottom flat and flat, which is critical for hydrodynamics and course stability. Low Pressure High Performance allows you to achieve a rigidity comparable to plywood, but at the same time retains the ability to fold the boat into a compact backpack.
The 390 is also a complex design, and it's made up of several independent cylinders, which is very safe, and even if one of the compartments is critically damaged, it's still afloat, and the bow is often fitted with an inflatable keel, which, when pumped, forms a complete keel. kielson, crashing into water and improving course stability at high speeds.
⚠️ Warning: Never leave a fully inflated NDND 390 under direct sunlight in hot weather unattended. The air pressure inside the cylinders increases proportionally to the temperature, which can cause seams to rupture or deformation of the structure.
Manufacture materials and strength specifications
The durability of the boat depends on the quality of the material used. For models of the class 390, which involve the use of motors with a capacity of up to 18-20 hp, reinforced polyvinyl chloride (PVC) with a density of at least 750-900 g / sq. m. This material is a multilayered “cake”, where a mesh of synthetic threads is melted between the layers of PVC, providing bursting strength. Modern fabrics often have a protective coating from the surface of the surface of the surface of the surface of the surface. ulphate and rotting.
Special attention should be paid to seams. In high-quality boats NDNDN 390 parts are joined by hot welding or gluing with two-component polyurethane glue. The second option is considered more maintainable in the field, although it requires strict adherence to technology. Seams should be smooth, without bubbles and non-proglys. Often in critical places, such as a shank and a transom, additional tapes are glued.
The trans is the heart of the engine compartment, and in boats of this size, it is usually made of moisture-resistant plywood (FSF) 18 to 24 mm thick and sheathed with a layer of plastic or the same PVC. sink-boardSome manufacturers are implementing a "hard canopy" system where the transom is connected to the bottom by rigid elements, which reduces the load on inflatable tubes when planing.
When buying a boat, pay attention to the presence of a pier around the perimeter. This is not just decor, but an important protection of the board from impacts on the pier, stones or the side of other boats.
Hydrodynamics and driving qualities on water
The 390 is a superb boat, especially compared to the pit-shaped ones. The lack of rigid elements in the bottom allows the hull to work as a unit, absorbing shocks against the wave. In planing, the boat behaves softer, less "knocks" on the water, which reduces crew fatigue during long transitions. This is especially true for anglers who spend 6-8 hours on the water.
But there's a downside to this: an inflatable floor, even a low pressure bottom, has more sailability and flexibility than hard aluminum, and when you're going against the wind or on a high wave, a boat can experience what's called "flippiness," which is compensated by the right load and the presence of a full-fledged load. keel It is also important to distribute the weight of passengers and cargo correctly, shifting the center of gravity closer to the transom for better planing.
The 390's speed specifications allow speeds of up to 40–50 km/h with a 9.9–15 hp engine and up to 60 km/h with an 18–20 hp engine (subject to proper loading). Gleaming mode is faster than heavy solder boats, thanks to its lower weight and better streamlined cylinders. Holding handles are often provided for high-speed control, and advanced models - spray-drill (spray line) in the nose.
| Parameter | Value for BND 390 | Comparison with hard-floor model 390 |
|---|---|---|
| Weight assembly (without motor) | 45-55 kg | 60-75 kg |
| Assembly time | 15 - 20 minutes | 25-40 minutes |
| Comfort on the wave | High (depreciation) | Medium (hard hit) |
| Load capacity | 600 kg | 700 kg |
| Price. | Above average | Medium |
☑️ Checking before getting on the water
Choice of outboard motor for boat 390
Selection of the engine for the boat NDND 390 - a task that requires a balance between the desired speed and safety. the maximum recommended power for such dimensions is usually 15-20 hp Installation of a more powerful motor (for example, 30 hp) is possible only if authorized by the manufacturer and the design of the transom is strengthened, but this often leads to overloading of the stern and reduced handling.
The optimal choice for everyday operation with 2-3 passengers on board is considered to be a 9.9 hp engine with the possibility of technical boosting up to 15 hp Such engines (for example, Yamaha 9.9FMHS or Hidea HD15FWS) have sufficient torque to bring the boat to full load plane, but remain economical. Two-stroke engines are preferred because of the lower weight, which is critical for transporting the boat in assemblies.
The height of the transom is an important aspect. For PVC boats, the standard height is 381 mm (15 inches) or 508 mm (20 inches). Incorrect height picking will either result in water being thrown into the cockpit (if the engine is too low), or cavitation and overheating (if too high). anticavitational I'm going to the lower unit motor to improve traction.
⚠️ Warning: Do not use motors with a forced water cooling system (pump) in shallow water without installing water intakes or lifting a lower unit.
Can I use an electric motor on the 390?
Yes, you can. The 390 NDND boats are perfectly combined with the 1700-2500 W electric traction motors, which are ideal for quiet fishing, fishing in restricted areas or use as an auxiliary engine, but the weight of the batteries should be considered, which will significantly reduce the useful capacity of the boat.
Tuning and additional equipment
Buying a basic version of the boat is just the beginning of the journey. To turn the NDND 390 into a full-fledged fishing or pleasure boat requires re-equipment. The first thing experienced owners change the regular seats (banks) for more ergonomic. Often install rotary seats on platforms mounted on stringers, which allows you to sit with your back or face to the movement, and also rotate 360 degrees.
The second important element is control-consoleInstallation of fiberglass or aluminum console allows you to permanently fix the steering, dashboard and sonar, which frees your hands and makes the boat at high speeds safe and comfortable, the steering cable in such cases is carried inside the cylinder or on board, protecting it from mechanical damage.
Also worth considering is the installation of an awning (cruising or parking), a moving awning transformer will protect from the sun and sudden rain, and a parking one will allow you to leave the boat in the open without the risk of moisture entering the cockpit. anchor-winchesholders of spinning and refrigeration bags attached to cylinders.
Competent tuning increases not only comfort, but also safety of operation. Control console and windshield significantly reduce driver fatigue and protect against oncoming airflow and spray.
Rules of operation, storage and care
For the 390 to last the stated 10-12 years, strict rules must be followed: never keep the boat deflated for a long time. After each operation, especially in salt water or hot weather, the boat must be washed with fresh water, dried and folded. Long-term storage in assembled form (pumped) is permissible only in shady, cool rooms.
When assembly and disassembly, avoid dragging the boat on the ground, sand or asphalt. Small abrasive particles can damage the PVC protective layer, which will eventually lead to material stratification. Use special transport wheels to move along the shore, if designed, or place an awning / mat under the bottom. Winter storage should take place at a temperature of not lower than -15 ° C, although room temperature is considered optimal.
Check the pressure in the cylinders regularly with a pressure gauge.defective) causes deformation of the bottom, reduced driving performance and increased wear of the seams.transfer) creates excessive tension of the fabric, which is dangerous when heated in the sun, the optimal pressure is checked on the "cold" boat before getting on the water.
How to properly seal a puncture in the field?
To repair the puncture, you'll need a lap-piece (PVC flap and glue). Clean and degrease the puncture site (acetone or alcohol). Apply the glue on the latto and on the boat, let it dry for 10-15 minutes until the stickiness disappears. Press the lap-piece hard, removing the air bubbles, and leave it to dry for at least 1-2 hours (preferably overnight).
Why is the boat NDND 390 not going to planing?
The main reasons: insufficient power of the motor for the current load, improper weight distribution (nose too up or immersed), too low pressure in the bottom cylinders, overgrown algae or damage to the keel. Also check the angle of inclination of the engine's lower unit - it may be chosen incorrectly.
What is the difference between NDND and NDNA (high pressure inflatable floor)?
NDND (low pressure) is softer to the touch, easier to collect, but more susceptible to deformation when overloaded. NDNA (high pressure,"AirDeck") is tougher, more like a hard floor, can withstand heels and heavy loads, but requires a more powerful pump to pump and is heavier in assembly/disassembly.
Can I use the 390 in winter?
You can use it, but with caution. PVC becomes less elastic in the cold and is susceptible to mechanical damage. You can't throw the boat on the ice, you can jerk sharply. You need to use non-freezing valve lubricant and special frost-resistant glues for repair. You can store in the cold, but you should put it into the heat gradually.