Which different anchor types are there?
There are many different types of anchor available for boats that come in several different shapes and sizes. In the past, heavy anchors were commonly used, which used their high weight to hold the boat. Today, stockless anchors attribute their holding force to their shape, not weight. An anchor can embed itself in the bottom in two ways: By hooking onto shingle or bedrock, or by digging into silt, mud or sand. This means that both the type of bottom and shape of the anchor are important factors to consider to be sure of a strong hold on the seabed.
These anchors have flukes that are positioned wide apart. They have a lower weight than other anchors and are also referred to as ‘lightweight’ anchors. They have a strong holding power due to their teeth, or "flukes" that are designed to dig into the bottom, helped by their long anchor shank. Even if the current or wind changes, they hold securely, but can easily be released again when the anchor is lifted.
Fluked anchors are particularly suitable for sandy, soft seabed. If the bottom is rocky, they can get stuck and it may not be easy to loosen them. Caution: mud can stick to the flukes, hindering them from digging in again. Check this when hoisting the anchor and clean if necessary.
Some types of fluke anchors can be taken apart or folded. This makes them ideal for smaller boats, where they can be stored in a box or anchor well. However, the pointed flukes can cause problems when stowed away. The following anchors are types of fluke anchors:
1 Plate anchor / Danforth anchor
Plate anchors, or Danforth anchors, named after their inventor, are very good for soft beds of silt, sand and clay. A further development of the plate anchor is the Fortress Anchor, where the fluke angle can be adjusted. This anchor type is popular on dinghies & small keel boats. On larger keelboats, a Danforth anchor can be carried as an auxiliary anchor for short periods in calm conditions.
2 Spade anchor
The fluke on this type of anchor is shaped concavely, similar to the shape of a spade. This gives the anchor a very high holding power.
Ploughshare anchors are similar to a plough in form and function. They are also often referred to as CQR anchors. Ploughshare anchors are allrounders for larger sailboats over 9 meters in length. They are heavier than fluke anchors and are usually hoisted by a bow roller. Particularly good at digging into soft ground, but even seaweed or rocks don't cause them much trouble.
The following anchors are types of ploughshare anchors or variants of such:
1 M anchor
M anchors are also called Bruce anchors. They are shaped like a shovel or a claw. They are easy to handle and consequently widely used. M-anchors are ideally suited for centrally mounted bow rollers, as they adapt perfectly to the bow shape.
2 Delta anchors
Delta anchors are a further development of the plough anchor. They have no joint between the "plough" and shank. The LEWMAR Delta anchor is listed in the Lloyds Register as a high-performance anchor due to its unique shank profile, is certified for commercial use and has a lifetime breakage guarantee.
3 Bracket anchors
These boat anchors feature a special bracket that keeps the anchor straight on the seabed, so that the flukes always face the bottom. Not suitable for all types of boats because of its rigid shape.
Some boat anchors are shaped in a variety of ways, giving them different advantages, such as stockless anchors and wing anchors.
1 Stockless anchor
Stockless anchors combine the advantages of a patent anchor with those of a weight anchor. They are particularly suitable for larger ships with a hawse.
2 Wing anchor
A wing anchor is a combination of a plate anchor and plough anchor. It is especially suitable for soft bottom surfaces. The heavy weight in the anchor tip allows it to dig in well.
Other anchor types
In addition to plough & fluke anchors and hybrid forms, a number of other special anchor types are very useful in particular areas or as an addition to the main anchor on board.
1 Stock anchor
Stock anchors are also called admiralty anchors. These are bulky weight anchors that hold about 10 times their own weight. This classic anchor is typically used on older ships. It consists of two arms with flukes at the end. At the other end, the stock is mounted to the shackle at ninety degrees to the arms, so that when the anchor lands on the bottom, the stock digs in, canting the anchor until one of the flukes catches and embeds. This anchor is perfect for stone, coral, weedy & clay-like bottoms.
2 Folding anchor
Folding anchors are also known as grapnel anchors or folding grapnel anchors. This anchor type has 4 arms which can be folded out. Due to the small space requirement, these boat anchors are easy to stow away. They are suitable for small boats, such as dinghies. Our folding anchors are often used as stern anchors, as they can be stored in an anchor chock at the pulpit when folded.
3 Mushroom anchor
This anchor type is used for mooring light vessels or sea markers for longer periods of time, but can also be used for smaller boats such as dinghies & inflatable boats. Mushroom anchors grip particularly well in sandy and muddy bottoms.
4 Drill anchor
Drill anchors can be used to moor at bank slopes or in mud. This anchor type is similar to a corkscrew and is screwed into the ground with a handle on the upper end.
5 Archipelago anchor
Archipelago anchors are wedged into crevices in the rock. Depending on the direction of pull, straight or angled archipelago anchors can be used. These anchors are also suitable for anchoring on river banks or mud, due to their shape.
6 Casting anchor
Casting anchors are not designed for classic anchoring. They are mainly used to pick up lost anchor gear. They can be used to lift other anchoring lines or chains and recover your own anchor.
7 Sea Anchor
A sea anchor can help to stabilise the position of a ship, e.g. in a storm. These anchors can also be used to slow down the vessel when mooring in marinas under sail.
Other anchor types
Which anchor for which seabed?
When you drop anchor, you may encounter a variety of different types of bottom surface: mud, silt, gravel and stones, clay, hard or soft sand. The bottom can also be flat or with depressions, ridges or elevations. Some anchor types are more or less suitable to certain types of seabed.
Sand is the best bedding for anchoring boats. Many, if not most boat anchors do a good job here. Fluked anchors can dig in well and provide excellent holding power.
2 Gravel, rocks, stones
In hard, stony bases it is not possible to dig in. The anchor must hook itself onto something to find a hold. The most suitable anchor is for this purpose is a ploughshare anchor.
Plate anchors with wide flukes are best for anchoring in silt. The shape of the anchor can easily dig in to the seabed. Mud and silt are often just the top layer, and as the anchor passes through it, it achieves better hold.
Ploughshare anchors are the best option for anchoring in weed. Nevertheless, bear in mind that the anchor could get caught on roots or protrusions that do not provide a secure hold.
How heavy must an anchor be for my boat?
Nowadays, the weight of a boat anchor is not necessarily the key indicator of its holding power. A heavy boat anchor does not always hold better, especially when the type of seabed is taken into account. Nevertheless, this doesn't mean that the weight of a boat anchor is totally irrelevant and there are guidelines for the minimum anchor weight depending on the length and weight of the boat. Many of the more popular anchor manufacturers have their own tables for each anchor type. You can find these on our product pages.
|Max. boat length||Weight||Min. anchor weight|
|Dinghy, Tender, Optimist||-||2 kg|
|4 m||300 kg||3.5 kg|
|5.5 m||800 kg||6 kg|
|6.5 m||1000 kg||8 kg|
|7.5 m||2000 kg||10 kg|
|9 m||3000 kg||12 kg|
|10.5 m||4500 kg||14 kg|
|12.5 m||8000 kg||16 kg|
|16 m||12000 kg||20 kg|
|18 m||16000 kg||24 kg|
|20 m||20000 kg||34 kg|
|25 m||30000 kg||40 kg|
|+ 25 m||+ 30000 kg||60 kg|
Material of boat anchors
Anchors are available in galvanised steel, stainless steel or aluminium and magnesium alloys. The least expensive are galvanised anchors. This material is very suitable in warmer, salty waters, such as the Mediterranean and the Caribbean. However, sand is abrasive to the galvanising protection and causes the anchor to corrode. Stainless steel is more prone to rust in warmer and salty waters. For very light boats an anchor made of an aluminium-magnesium alloy is recommended.
Where are boat anchors stowed on board?
Ploughshare anchors and Bruce anchors can be fixed via a bow roller and are often used in combination with a windlass. Plate anchors can be taken apart and stored in an anchor well. It can take up to 10 minutes until the anchor is assembled and ready for use. Fortress anchors usually have a storage bag for stowing them onboard. For stern anchors there are special holders for mounting them on the stern, bathing ladder or pulpit.
Anchors stowed on board
Will the anchor hold my boat?
An experienced skipper will be able to see if an anchor is really holding the boat in place by taking bearings with place markers or using other boats as reference. By feeling the anchor chain or rope, it is easy to tell when the anchor is slipping over the bottom surface. In this case, more chain should be given or the anchor spot should be changed.
People often worry, especially at night, whether their anchor will hold. Many electronic devices that use GPS can send out an alarm should the anchor spot change. Such anchor monitoring programmes can be downloaded to your smartphone as a handy app.
Marker buoys and mooring buoys
A marker buoy helps to keep the position of the anchor in view and thus allows any changes to be quickly seen. This is particularly helpful and recommended if anchoring at greater depths or if you are unsure of the holding qualities of the seabed. In busy anchor bays, however, it is not advisable to use an marker buoy, as they can easily get caught in another boat's propellers.
Marker buoys and mooring buoys
There is no single best anchor for all boats. The most suitable anchor always depends on the type and condition of the seabed to be anchored to. To help when shopping for an anchor, think about where you will be using it the most. If you will be taking your boat to waters where there could be different types of seabed, you might want to consider purchasing a second anchor for backup.