A properly chosen anchor is not just a piece of metal at the end of a rope, but a guarantee of your safety and a comfortable rest on the water. floater They make the mistake of relying on intuition or advice from their neighbors in the parking lot, which often leads to drift at the most inopportune moment, and the wind, current and bottom topography dictate their own conditions that cannot be ignored.
In this article, we will examine the physical principles of keeping a boat in place and learn how to calculate the required weight of a cargo with mathematical precision. PVC boats 3.20 meters long and 4.20 meters long require completely different approaches to anchoring. For a clay bottom, the weight of the anchor can be reduced by 20-30% compared to sandy soil with the same sailing area.
To start with, the anchor system needs to be balanced, because an anchor that's too light will not get caught, and an anchor that's too heavy will cause problems when lifting and can damage the transom or the cylinders, and let's identify the key factors that influence the choice.
Physics of the process: what depends on the strength of demolition
Before you grab a calculator, you need to understand what forces are acting on your boat. sailability Even a slight breeze creates a tangible pressure that the anchor must compensate for.
The second important factor is depth The deeper the rope, the longer it takes, and the more weight it adds to the overall load on the anchor, the rope should not hang vertically; it should lie on the bottom, forming a cathenar (provis) that extinguishes the jerks from the waves.
There is a common misconception that an anchor should weigh 10 percent of the displacement of a boat, which is a gross mistake that would only work in calm in deep water, and in reality, the formula is more complex and takes into account the area of the projection of the board.
- 🌬️ Wind load: Wind strength increases exponentially; a gust of 15 m/s creates pressure 4 times greater than a wind of 7.5 m/s.
- 🌊 Current: Water is denser than air, so even a weak current creates significant resistance.
- 🎣 Type of activity: Active fishing with echo sounder requires a more reliable anchor than simple swimming in the bay.
Understanding these forces helps avoid situations where the anchor crawls down the bottom, scratching the ground and scaring the fish. Always assess the situation before throwing the anchor.
⚠️ Warning: Never tie the anchor phala to the transom handles or parts of an inflated balloon! A sharp jerk (for example, from a passing boat) can lead to puncture of PVC or the separation of handles, which can lead to the loss of anchor or boat.
Classic formula for calculating the weight of the anchor
To determine the exact mass, there's a time-tested formula that professionals use, which takes into account the length of the hull and its width, which is directly related to displacement and sailing.
The formula is as follows: Anchor weight (kg) = (Length × width) / 100Here, length and width are taken in centimeters, which is a base value, which is then adjusted according to the operating conditions.
Let’s take an example of a popular one. PVC 3.20 boats We're going to multiply it into centimeters: 320 cm and 140 cm, multiply it: 320 × 140 = 44800. Divided by 100, we get 448. But it's not just kilograms, in the classic simplified version for small craft, often using a coefficient that depends on the type of anchor. Weight = 0.15 × Length (cm) for calm water.
However, for foot-bar (Denforth, Hall) that burrow into the ground may have less weight because they are held by the ground. For them, the weight is often calculated as 1 kg per 1 meter of boat length, but adjusted for wind.
If you plan to fish in the river with the current, add to the estimated weight of the anchor at least 30-40% of the stock. Current acts on the underwater part of the boat and the fishing line more than the wind on the surface.
Don't blindly trust one formula. Always make adjustments for the "sailing" of your particular assembly. Having an awning, a high motor, or a large number of gear increases sailing.
Table of correspondence of the weight of the anchor to the length of the boat
So, to avoid doing the calculations every time, you can use a table that's prepared, and it's based on average wind loads and typical dimensions. fly-boat.
| Boat length (m) | Type of anchor | Min. weight (kg) | Wholesale weight (kg) | Max. Weight (kg) |
|---|---|---|---|---|
| 3.0 | Cat/Mushroom | 2.0 | 3.0 | 4.0 |
| 3.0 – 3.5 | Pawp/Cat | 3.0 | 4.0 | 5.0 |
| 3.5 – 4.2 | Pawp/Plow | 4.0 | 5.0 | 6.0 |
| 4.2 – 4.8 | Pawny/Admiral | 5.0 | 6.0 | 8.0 |
| more than 4.8 | Pawp/Plow | 7.0 | 8.0+ | 10.0+ |
The data in the table is relevant for moderate wind conditions (up to 5-7 m / s). If you go out into a storm, no calculations will help - in this weather, the weather is not very good. PVC I'd better not go out.
Note that maximum weight is limited by transax strength and ease of use: An anchor weighing more than 6-7 kg is already difficult to safely lift from a depth of 3-4 meters without overturning a light boat.
☑️ Checking before getting on the water
Design choice: cats, paws or mushrooms?
The type of anchor affects the required weight as much as the size of the boat. Other designs interact with the bottom soil in different ways. flyboat Not only the holding power is critical, but also the safety of the lift.
The most popular option is cat anchor. It folds its paws, which is convenient for transport in a bag, but cats often get stuck between rocks, and if you pull a cat that's stuck, you run the risk of damaging the balloon or rolling over.
Paw anchors like Denforth have great holding power on sand and silt, they burrow into the ground and hold a boat that weighs 10 to 15 times their own, but on a rocky bottom, they can just slide across the surface.
- ⚓ Cat anchor: It's versatile, compact, but it can get stuck, perfect for mixed soil.
- 🛡️ Paw anchor: The best holding power on soft ground, but takes up more space in the folded form.
- 🍄 Anchor-mushroom: It works by weight alone, and it's suitable for a muddy bottom where it sticks, but it's useless on a hard bottom.
For fishing in a snag or on a rocky bottom, experienced boaters use junctionThey have a removable heel or a special mechanism to release the anchor if it gets stuck, pulling it over the top.
⚠️ Note: When using sharp-leg anchors (cats, paws) on PVC boats, be sure to use cranes or cylinder protective linings at the place where the rope sags. The sharp angle of the anchor when rocking the boat can easily damage the material.
How to make a detachable anchor yourself?
Take a normal cat. Attach a thin, strong line (0.5-0.8 mm) to the bottom (where your paws converge); at the second end of the line, take it to the ring at the top of the anchor; when you get stuck, you pull on this line, the paws turn around, and the anchor is released.
Anchor shaft: length, material and fastening
The weight of the anchor is only half the battle. The second half of success is the right one. anchor-falseMany beginners make the fatal mistake of using a chain or a rope that is too short.
The golden rule of anchoring is that the phala should be 3-4 times as deep as the parking lot. If you stand at a depth of 2 meters, the rope should be 6-8 meters. This provides a gentle angle of thrust, allowing the anchor to burrow, rather than dragging along the bottom.
The material of the fala also matters. PVC boats The chain is too heavy for light boarding and can damage the balloon; a short chain spindle (0.5-1 meters) is allowed only for heavy anchors on large boats, so that the anchor rests on the chain and not on the rope.
The slack should be only for pyre And you can see it on the bow of a boat that's connected structurally to a transom plate or reinforced by a sticker, and you can tie it to the carry handles, and you can actually lose anchor.
The optimal material for the PVC boat is a wicker polypropylene or nylon cord with a diameter of 6-8 mm. It does not sink, rot and is pleasant to the touch, unlike a hard fishing line that can cut your hands.
And remember, this is a little float that's anchored on a separate line, and if the anchor is stuck, you take the boat to the boat, pull the anchor by the tail, and you can easily get it out of the ground.
Frequent errors and safety practices
Even if you know the theory, it's easy to make mistakes in practice. anchorageNever, you hear, ever anchor from the stern of a boat!
If the boat turns to the wave or the wind, it will burrow its nose into the water. For an inflatable boat with low sides, it is deadly: water over the side will go inward, and the boat can flip over or sink in seconds. The anchor always throws strictly from the nose.
The second mistake is the lack of a knife. Anchor knife If the tile is wound onto the engine propeller (which often happens in the wind), you will need to cut the rope instantly so you don't lose control.
- 🔪 Missing knife: Risk of losing a boat or motor when winding a phala.
- 🚫 Anchoring from the stern: High risk of boat overturning on the wave.
- 🧶 Too long.