Inflatable swimmers often face a dilemma: take the first cargo they get or spend time on calculations. anchorage Not only does the comfort of fishing depend on the safety of the crew on the water, but an anchor that is too light will not hold the boat in a gust of wind, and an excessively heavy one will put an extra load on the transom and cylinders.
Inflatable boats are highly sailable because of inflatable tubes and people sitting on cans. PVC boats They are more easily carried by the current and wind, which requires a special approach to the choice of anchor system, and ignoring the physics of the process can lead to demolition in shallow waters or, conversely, to the fairway with intensive navigation.
In this article, we will look at proven calculation methods, compare different types of anchors and determine what weight is optimal for your vessel. anchorage This will help you avoid many unpleasant situations on the water.
Basic principles for calculating the weight of the anchor
There are several empirical formulas that have been used by boatmasters for decades to determine the required mass of an anchor, and the most common and proven practice is that the weight of an anchor should be approximately 10% of the length of a vessel in meters. correction They are very small because of their low weight and high weight.
Another approach is displacement, and it's thought that the mass of the anchor should be about 10 percent of the displacement of the boat in tons. PVC With two passengers and equipment, the total weight can reach 300-400 kg, which formally requires an anchor weighing 30-40 kg. In practice, it is irrational to carry such a cargo in an inflatable boat, so the owners make compromises, compensating for the weight of the length of the anchor falin.
The key here is not so much the net weight of the metal as the anchor's ability to cling to the ground. hookability It's better than a heavy piece of concrete that just sits on the bottom, so you should be looking at the design of the paws, not just the kilograms.
Dependence of the choice of anchor on the length of the boat
The length of the vessel is the primary reference point for equipment purchases. For compact single-seat models up to 2.5 meters long, the requirements are minimal, as the wind resistance area is small. In this segment, 1.5-2 kg is often enough for calm water.
As the length increases to 3-3.5 meters (standard for two-seater boats), sailing increases proportionally. anchorage Weight from 3 to 5 kg. Less weight may not withstand the load in the side wind, and the boat will begin to turn the side to the wave, which creates a dangerous situation.
For large boats longer than 4 meters, which are often equipped with console controls and windshields, the requirements for the anchor system increase significantly. cross-board The weight of the anchor must be held in suspension during the course, otherwise damage is possible.
Below is a table that systematizes recommendations for the weight of the anchor depending on the dimensions of the swimmer:
| Boat length (m) | Recommended weight of anchor (kg) | Typical displacement (kg) | Features of operation |
|---|---|---|---|
| 2.5 | 1.5 - 2.5 | 200 | Calm water, rivers with slow current |
| 2.5 - 3.2 | 3.0 - 4.0 | 200 - 350 | Excitement up to 0.5 m, moderate wind |
| 3.2 - 4.0 | 4.0 - 6.0 | 350 - 600 | Large reservoirs, possible wind |
| 4.0 | 6.0 - 8.0+ | 600+ | Open water, long parking lots |
Influence of soil type and wind strength
The weight of the anchor is only half the equation. The other half is the specifications of the bottom of the body of water. On sandy or slurry soil, the anchor is buried and held dead, even if it is lightweight. soil-seed.
It's a very different situation on a rocky or pebble bottom, where the anchor can just slide across the surface of the rocks without finding a hook, and it requires either an increased weight to move the top layer of the pebble, or a special anchor design (for example, a special structure for the anchor). denforth long-legged Cat.If you plan to fish on rivers with a rocky bed, the weight of the anchor should be increased by 20-30% of the estimated.
Wind is the main enemy of anchoring. The force of wind pressure on the boat increases exponentially. With low wind (2-3 m / s) can suffice and 2 kg, but when increased to 5-7 m / s (fresh wind), the load on the anchor rope increases many times. In stormy weather, even a heavy anchor can not hold the lightweight. flyboatIf the anchor cable is not properly organized.
⚠️ Warning: Never tie anchor falin hard to a nose duck or a ditch in high wind or current. A sharp jerk when turning a boat can rip out a duck with meat or, worse, turn the boat over. Always use a rubber shock-absorbing insert or hold the end of the falin in your hand (in a glove), feeling the tension.
How does the anchor behave on different soils
On silt, the anchor sinks deep, creating a tremendous holding force; on hard clay, the paws can slide if the angle of attack is wrong; on grass, the anchor often gets tangled in algae, which pull their paws out of the ground.
Anchor design: what is best for PVC
The choice of anchor shape for an airboat is dictated not only by efficiency, but also by safety for cylinders. Classic admiralty anchors with a transom slat (spine slat) are dangerous for PVC, as they can damage the material when lifted.
Cat anchor is the most popular option among fishermen. Four sliding legs provide a reliable grip on rocks and driftwoods. The main advantage is compactness in its folded form. However, the cat has a disadvantage: it can get stuck in stones, and then you have to make efforts to lift, which is risky for the cat. flyboard.
Denforth's anchor (or its analogues) has excellent holding power on sand and silt. Its paws are large and deep in the ground. PVC boats are made with special lightweight versions with plastic legs weighted with lead. They are safe for cylinders, but useless on a hard rocky bottom.
- 🐙 Cat anchor: versatile, foldable, good for stones, but can get stuck.
- ⚓ denforth: Perfect for sand and silt, compact but afraid of hard ground.
- 🪨 Gravitational anchors (pancakes, stockings): just lie on the bottom, do not scratch the cylinders, but have a low holding power relative to weight.
- 🎣 Homemade options: Often made from brake discs or concrete blocks, but they are bulky and traumatic to the boat.
For PVC boats, the priority is cylinder safety: choose anchors without sharp protruding corners or use protective pads.
The role of anchor rope and chain
Many beginners make the mistake of tying a heavy anchor with a short rope, which is a gross violation of anchoring rules. The anchor rope (falin) must be long enough to lie on the bottom and extinguish the boat's jerks. The optimal length of the falin should exceed the depth at the parking lot by 3-5 times.
Using a small chain (1-2 meters) between the anchor and the rope is a professional technique. The chain, lying on the bottom, presses the spindle of the anchor, making the legs work more efficiently. shock absorberFor light PVC boats, a chain of 6-8 mm diameter is enough.
The material of the faline itself is also important: synthetic cables (nylon, polypropylene) are floating and do not rot, but can be rubbed against stones. Natural cable (canifas) sinks and feels pleasant to the touch, but rots if stored improperly. For most tasks, a synthetic cord with a burst load of at least 200-300 kg will suit.
☑️ Checking the anchor system before exit
Practical tips for installing an anchor
The correct anchoring is more important than its weight. When you approach a parking lot, you need to stand against the wind or current (whichever stronger). The anchor is thrown or lowered from the bow of the boat when it still has a slight inertia stroke. Abrupt braking with the anchor at full speed can cause the boat to turn over over the nose.
Once you touch the bottom, you have to slowly roll back, picking the rope slack until the anchor is buried, and then you can poison the falin to the right length. keeps Or the falin is too short.
When lifting the anchor, never pull it vertically upwards with muscles if it's stuck. Go as close to the anchor (above it), pick a rope slack and tie it to the nose duck. Then move forward slowly or use the wave to stir the anchor. turret Or turn the boat over.
⚠️ Attention: It is strictly forbidden to tie the anchor to the stern of the boat in the presence of wind or current. The boat will turn on the side to the wave, it will begin to tilt dangerously and draw water with the sides, which will lead to a rapid overturn.
Carry a second, lightweight anchor (such as a folding cat weighing 1.5 kg) as a spare or for use as a shipwreck (stern) anchor to fix the boat in the stretch.
Frequently Asked Questions (FAQ)
Can a bunch of stones or bricks be used instead of an anchor?
You can only use stones as a last resort, but it's not effective. Smooth stones don't hold well in the current, sharp edges can damage the cylinders of the boat when lifting. Brick is too heavy for its volume and fragile. Better buy a specialized stocking anchor that you fill with stones on the spot, or an inexpensive folding anchor.
How long should the anchor end be for a boat of 3.2 meters?
For a boat 3.2 meters long, the minimum length of the faline should be 15-20 meters. This will allow you to anchor at depths up to 4-5 meters, taking into account the required angle of tension. The short end (5-7 meters) will work as a plumb, and the anchor will constantly pull out at the slightest displacement of the boat.
Do I need to lubricate the metal anchor before storage?
After each fishing, the anchor should be washed with fresh water (especially after salt water) and thoroughly dried. Then it is recommended to lubricate the moving parts (vertlugas, paw axles) with a consistent lubricant type of lubricant. litol or CiATIM, and the body itself to cover with anticorrosive composition or simply store in a dry place to avoid rust, which quickly destroys the thin metal of cheap anchors.
What if the anchor is stuck in the stones?
Don't pull the boat sharply. Try to approach the anchor from different sides, changing the thrust vector. If you have a sonar or a depth map, determine the relief. In extreme cases, if the anchor is not pathetic, you can tie an additional rope to the cut ring (if you have one), to turn around. If the anchor is valuable and you can't get out, sometimes you have to cut the falin, so always have a sharp knife on board.