Anchor Selection Guide
You’ve just bought that “new” 44 foot Albin Sundeck trawler and she’s everything you wanted in a trawler. After upgrading some marine electronics, you will be ready to do some cruising. You can’t wait to drop the hook and enjoy your time on the water.
But wait; gunk holing is your goal but is your ground tackle the right one to do its job? It came with the trawler so it should be, shouldn’t it? So what is the best kind of ground tackle for you boat; is your anchor the best one for your cruising?” I get asked that question a lot, and the answer is that the type of bottom, be it mud, grass, sand, coral or rock, will determine the appropriate choice of ground tackle, as will the size of your vessel. Some anchoring situations may also call for more than one anchor.
Wind conditions will also be involved in how well ground tackle holds; every time the wind speed doubles, the force on the boat and her ground tackle will increase by four times.
Sizing ground tackle for your boat reinforces the “bigger is better” concept; you really cannot have too much anchor. If your engine fails and you are drifting toward an open inlet, having a appropriately sized anchor ready could save you and your boat. However ground tackle choice also has some practical issues involved; raising an anchor by hand with no electric windlass would be strenuous and therefore requires light and effective ground tackle.
Anchors must develop enough resistance in the sea bed to endure the environmental forces on the boat–the wind and the tides. An anchor’s capacity to develop resistance is completely dependent on its capability to penetrate the sea bed. The selection of an appropriate bottom for anchoring is a great deal more of a critical factor than the style of the anchor. You must take the anticipated bottom conditions into account when choosing your anchor.
Aboard my trawler the Patricia Ann, I use a 35 lb. Lewmar CQR. It has held in sand and mud bottoms in my cruising area without ever pulling free. It sets easily.
Here is a breakdown of possible options, based on the sea bed conditions:
- Sand: Fine–grained sand is rather easy for anchors to penetrate and offers dependably good holding power with predictable results. Fluke anchors are the best type in sand.
- Mud: Mud has low shear strength, and requires anchor designs with a broader shank–fluke angle and fluke area. This allows the anchor to go in deeply to where the mud has greater sheer strength. Mud bottoms are often only a thin layer of mud over clay, so anchors that can penetrate through the mud to the underlying material will hold better. Hinged plow anchors and CQR anchors work well in this setting.
- Rock and Coral: Holding power is most reliant on where you choose to drop the hook, rather than the type of anchor. Plow type anchors, with high structural strength to sustain the high point loads, normally work the best. These anchors include the Claw, CQR, and Delta.
- Shale, clay, and grassy bottoms: These are tough bottoms for all anchor designs, with the weight of the ground tackle being the most significant factor in determining penetration and holding power. CQR and Delta anchors are found to be good due to their capability for penetrating vegetation. However, these conditions have a high likelihood of failing to set, due to the ground tackle catching on grass, roots and protrusions, rather than something rock-solid.
The following is a breakdown of the 5 styles of anchors. Comparative costs are based upon the appropriate weight of anchor for a 40 foot powerboat.
1 – Fluke Anchors
- Pros: Good holding power in sand. Can be had in light weight aluminum. Low priced.
- Cons: Limited or no holding in rock, mud, grass, or clay bottoms.
- Brands: Fortress, Danforth, Guardian
- Costs: $109.00 for 40 ft boat
2 – Claw Anchors
- Pros: Inexpensive. Sets quickly and reliably in most sea beds and resets well. High–strength one–piece design. Roll stabilized.
- Cons: Difficult to stow without rollers or chocks. Limited holding power in mud or soft sand.
- Brands: Lewmar Claw, Manson Claw
- Costs: $109.00 for a 40 ft. boat
3 – Non–Hinged Plow Anchors
- Pros: Extremely strong construction, made from heat–treated high–tensile steel. Great in sand and good in mud.
- Cons: Limited or no holding in rock, grass, or clay bottoms. Expensive
- Brands: Delta, Anchorlift
- Costs: $278.00 for a 40 ft. boat
4 – Non–Hinged Scoop Anchors
- Pros: Roll bar for easy resets. Strong high tensile steel construction. Self–launches from most bow rollers. Good holding in sand and mud. Sets easily.
- Cons: More expensive
- Brands: Rocna, Manson
- Costs: $599.00 for a 40 ft. boat
5 – Hinged Plow Anchors
- Pros: Great reputation and very strong construction. Stows easily on an anchor roller, and sets well in most sea beds. Penetrates weeds, sand, and mud, and hooks on rocks. Good holding power in many conditions. Sets easily.
- Cons: Requires large size for given boat size. Very expensive.
- Brands: CQR, Manson
- Costs: $749.00 for a 40 ft. boat