We all know an anchor’s shape and function. But I have always wondered how it worked since I was a kid. Isn’t it incredible how a stubby piece of metal can hold down a huge vessel? Fast forward to today, I have owned a boat for a couple of years, learned proper mooring and docking skills, and finally came up with a thorough and accurate answer.
Picking up this information will help you use an anchor appropriately. Also, “How do most anchors hold a recreational boat in place?” is a question you might encounter when taking boating exams. In short, the anchor reaches the seafloor and buries itself into the sand. Due to the unique shapes, when the boat moves around on the water, it can dig more cavernously and lock the boat in place.
However, there are multiple factors that affect the sufficient level of anchoring. Let’s explore this further!
Table of Contents
How Does It Work
An anchor is a device that connects a boat to the bed of the lake, sea, or river to hold it in place. Each type has a slightly different working principle. But generally speaking, once dropped out of the ship’s hull, the anchor will sink right down. Due to the device’s heaviness, the pointed flukes will burrow deep under the sand and stay put.
When the wind or current make the boat drift slightly, there will be more pressure applied on the anchor, causing it to dig even deeper. Besides the anchor’s weight, gravitational force must be calculated carefully to establish a reliable and capable anchoring system. Oftentimes, the captain gently steers the ship in the reverse direction to help set the anchor. Proper setting will provide more stability and resistance.
For better visualization, watch this video on ULTRA anchor animation from ULTRA Marine. However, these temporary anchors (ones that can be pulled up easily when you finish using) are only for regular vessels that operate in shallow water. For offshore constructions or oil rigs, permanent anchors must be installed by certified engineers using more complex, computer-controlled systems.
Different Types of Anchors
In the past, most anchors were made from metal, relying on their heavy weight to prevent the boat from drifting. Sand, stones, and lead were often used to add heaviness to the device. Back then, the only shape was the anchor that had pointed flukes on the edges.
Over time, many more types of anchors have been invented for different purposes. To anchor most effectively, there are many aspects of the device you must consider.
There are three basic anchor shapes:
- Fluke-style or Danforth anchors: These are stockless and lightweight anchors, usually made of aluminum. Their mechanism is similar to traditional ones. A fluke-style anchor holds a recreational boat in place by burying the flat flukes in the seabed. But they are easier to retrieve due to the compact and flat shape.
- This type is one of the best options when it comes to anchoring in mud and sand. Outside of these two bottoms, it doesn’t perform well. Because of its limitation, fluke-style anchors are mostly used for vessels under 38-foot long. Larger vessels sometimes have a Danforth type as a secondary or stern anchor.
- Mushroom anchors: As implied in the name, these look like a mushroom. Once sinking down the bottom, they form suction, filling the cap with mud or sand and keeping the boat in place. Though the shape doesn’t offer strong holding power, it is more convenient and easier to use.
- Small fishing boat owners should choose mushroom anchors. They work well for most rivers and lakes. You can buy a complete kit of this anchor type on Extreme Max or Newport Vessels for under $50.
- Plow-style anchors: These anchors are a good choice for most recreational boats because they can adhere incredibly well to multiple bottom conditions, including rocky ones.
There are many other types of anchors, such as claw, grapnel, or wing anchors. Though they are not as popular, each one is designed for specific weather and seafloor conditions. A vessel should have at least two anchors to swap out if needed.
The materials of an anchor decide its strength, heaviness, and durability. Most importantly, the materials must be heavy and able to resist long-term corrosion. Protective methods like electroplating or galvanization are often applied to high-tensile steel to improve their resistance. Over time, the galvanization will wear out, requiring the owner to reapply it periodically.
Corrosion-resistant materials like aluminum and stainless steel do not need to be galvanized. Stainless steel is one of the heaviest materials while aluminum is on the lighter side. Hence, most aluminum anchors rely on its shape to secure the boat.
As technology develops, lightweight materials like fiber-reinforced composites or carbon-fiber can be used. These are extremely reliable, long-lasting, and able to resist corrosion, rust, and mold. However, the development of such anchors can be costly and uneconomical.
Understandably, larger vessels need bigger anchors. Choose the anchor size based on the vessel overall weight. You can always refer to the size guide chart before purchasing.
Besides the weight, anchors are rated by their holding power. This number is formulated based on environmental factors, like wind speed. The rule of thumb is an anchor of 90 pounds can safely hold a 20-foot vessel in winds up to 20 mph.
What to Consider When Anchoring
Now, you know what anchors suit what boats and the working principles. But there are other factors that contribute to sufficient anchoring.
1. Anchor rode
Random rope or chain won’t work, you need to select the right anchor rodes. Nowadays, anchor rodes consist of chain and nylon rope for optimum holding power and durability. Chain is heavier and adds weight to the overall anchor, helping it sink more deeply into the seafloor.
Meanwhile, nylon rope is elastic, light, flexible, and easy to manipulate. It provides great shock absorption against sea waves. Therefore, most of the rode is nylon rope, and the end where the rode connects with the anchor is chain.
When you’re done choosing the rode, you need to calculate the proper length. Use a ratio of 1:7, which means one foot of anticipated water depth requires seven feet of rode.
2. Seabed composition
Last but not least, consider the water you’re about to tackle. When going through rocky riverbeds, a grapnel anchor is ideal. On the other hand, a mushroom anchor will be excellent for soft bottoms like clay or sand.
Setting up an anchor might be complicated and time-consuming. But it is imperative for safe boating. Once an anchor burrows itself into the sea bed, it will hold your recreational vessel in place regardless of strong wind or running current.
We hope you’ve gathered enough information about how do most anchors hold a recreational boat in place. Please share your knowledge and experience in the comment section. Learning from a fellow boat owner is always exciting. We look forward to hearing from you!
Working to create content for Marine Talk has always been a fascinating experience. I get to travel, absorb knowledge about boating, and tackle all the issues when we sail into freedom!