A Note On Anchor Types, Names and Trademarks
On the boatffittings website we have a variety of anchors in terms of type, size and material. Many anchors have a trademarked name, such as a Bruce or Delta, and a generic name like Claw or Plow. This is much the same as how Hoover is a trademarked name for their range of vacuum cleaners. Design patents expire after approximately 20 years, after which manufacturers are free to clone an anchor design but as trademarks do not expire, copies or clones of a certain anchor designs cannot use the trademarked name.
The Bruce is an excellent all-purpose anchor as it performs well in most sea bottoms including mud, sand, grass, rock, and coral. It sometimes has a hard time penetrating harder surfaces, such as clay.
Due to the three-claw design, the Bruce often sets more easily than other anchors. It also resets easily if it is ever broken loose. On the downside, there are other anchors that have a higher holding power per kg of anchor than the Bruce.
- Pros: Performs well in most conditions. Sets easily.
- Cons: Holding power per kg not as great as some other anchor types.
- Sea-bed types: Performs well in most bottoms; Struggles in hard bottoms such as clay.
The Delta anchor a plow style anchor. The Delta is one of the most popular anchor designs in use on boats today, and is the standard anchor of choice used by many boat manufacturers.
It has a very reasonable holding power per kg (about 50% more than the Bruce).
The Delta anchor performs well on most sea-bed types, struggling the most in rock.
- Pros: Performs well in most conditions. Fits most bow rollers.
- Cons: Stowage can be awkward.
- Sea-bed types: Performs well in most bottoms; Struggles in rock.
The Danforth, or Fluke anchor, remains a very popular anchor choice amongst boaters. The Fluke performs excellent in mud and sand, potentially the best of any anchor style.
The downside is that outside of these bottoms, it does not perform at well. Therefore it is a mud/sand only anchor, which fortunately is what most bottoms are comprised of.
Whether or not it is used as a primary anchor, a Fluke anchor makes an excellent choice as a secondary or stern anchor.
- Pros: Performs well in mud and sand. Arguably the most popular general purpose anchor. Stows easily on most bow rollers.
- Cons: Does not perform well outside of mud/sand.
- Bottoms: Performs excellent in mud/sand. Performs poorly in other bottoms.
Folding / Grapnel Anchor
A Grapnel Anchor is generally used for small boats such as Kayaks, Dinghies, Canoes, etc. It’s also popular amongst fishermen.They fold up very compactly and are easy to stow.
A Grapnel’s holding power comes from hooking onto another object, such as a rock. When it does hook, it can create immense holding power, which can also make retrieving the anchor difficult in such cases.
- Pros: Great for use as a lunch hook. Folds to allow for compact storage.
- Cons: Not appropriate for non-temporary anchorage.
- Sea-bed types: Rock or other situations when it can hook onto an object.
How it's connected
The anchor line is shackled to the anchor at one end and then connected by rope to an attachment point in the boat (usually in the anchor locker) so that if the anchor is accidentally dropped, the whole anchor line will not simply run-out and drop over the side. The permanent connection to the boat should be a knot that can be easily undone under pressure, just in case you need to ditch the anchor quickly and easily in the case of an emergency.
Anchor Lines, How Much Chain / Rope To Use
Having chosen your anchor there are also choices to be made for your anchor line. It is common to use entirely chain, but you may prefer to use a combination of chain at the anchor end, joined to rope which is easier to handle when pulling up the anchor for two reasons, firstly the rope is kinder to hands (as well as deck and fittings) than chain, secondly if a lot of line has been let out in deeper waters the combined weight of anchor and chain can get difficult to manage when pulling it back in.
I once anchored in fairly deep waters to do some fishing and it was only when we decided to head home that I realised that the combined weight of chain and anchor was only just possible for me to haul up. (Just picture all that chain in you anchor locker, and imagine lifting it and the anchor all in one go – not necessarily what you think about when letting it out.) After this experience I decided to switch to a combination of chain and warp. The next question is how much chain to keep? Between 5 and 10 meters of chain should be used between the anchor and warp. The weight of this length of chain has an important function in acting as buffer between the anchor which wants to remain flat on the sea bed, and the warp which obviously needs to rise up to the level of your boat. Each time your boat tugs on the anchor line with waves and current the length of chain lying on the sea bed moves and absorbs the energy of the pull, but crucially at the anchor end remaining flat on the sea bed.
Scope is the amount of chain or warp let into the water. The amount of scope depends on the depth of water and whether chain or warp is used. Check the depth and tidal range. Use a scope of anchor cable of at least 4 x the depth for chain and 6 x for rope/chain combinations. The golden rule of anchoring is: if in doubt, let more out (but don’t forget to look at where you might swing to when wind and tide change directions of course, eg other boats, shallow waters, navigation channels)
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