Published: Oct 31 2013
Anchoring is one of the least understood aspects of boating. It may be because anchoring involves both art and science. First, there is the physics of anchoring, such as knowing how heavy an anchor needs to be to secure the boat. Next comes the technique of “setting the hook,” or getting the anchor to hold. Regarding the latter, there are as many opinions as there are boats. This article will stick to the science question: choosing the right anchor for your boat.
Knowing you have the right anchor for the job will make a day on the water much more relaxing, and will certainly help you sleep well at night if an overnight is part of the plan. Anchors can also be important for boat safety. If a boat loses power for some reason and is drifting toward shore, dropping anchor and getting a firm hold will keep you safe until you can solve the problem or until help arrives.
There are two things to consider when buying an anchor: boat size and bottom conditions. The size of the boat determines how big (heavy) the anchor needs to be, and the bottom conditions determine the anchor style. The weight of the anchor can hold a boat in calm waters, but in most conditions, you will need to make sure the hook is well set, and hooks are designed for various bottom surfaces.
Fluke anchors consist of a shank and two or more hinged spades, or flukes, that dig into the bottom when the boat pulls against the anchor. The hinge is important because it allows the anchor shank to rise while the flukes remain angled downward in the bottom’s surface. Fluked anchors are ideal for areas where the bottom consists of mud or sand. Flukes can be lighter to hold a larger boat (a 15-pound fluke anchor can hold a 32-foot boat), and stow flat for easy storage.
Plow anchors are what the name implies: a metal wedge (plow) attached to a shank. The wedge is curved backward and the anchor resembles a large hook. Use a plow anchor if you are anchoring in heavy grass, rocks, or mud. Because they are heavy, large, and curved, they are not easily stowed. Most plow anchors require a roller on the bow of the boat where the anchor can be easily deployed, retrieved, and tied down when in transit. Plow anchors are also heavier than fluke anchors — a 20-pound plow anchor is required to hold a 32-foot boat, for example.
Think of a claw anchor as similar to a plow anchor but with multiple extensions instead of a single plow. Claw anchors work well in rocky conditions; with multiple claws, they are more likely to find a hold. Because of their shape, claw anchors also require a bow roller for deployment and storage. They are a bit heavier still than the plow: a 22-pound claw is required to hold a 32-foot boat.
Also known as the yachtsman’s anchor, the fisherman’s anchor is the kind you see on tattoos and restaurant menus. They consist of a shank with a barbed hook on each side. These anchors are not used much anymore outside of decorations for yacht clubs and harbors. A T-bar at the top of the shank forces the hook to rest perpendicular to the surface, giving the hook the right angle to dig in to sand, mud, or rocks. The required weight for a 32-foot boat with this type of anchor is a whopping 75 pounds, which explains why they are not very common.
For smaller boats and day trips, mushroom anchors can work well, especially in mud or sand. Made in the shape of an upside down mushroom with a lip around the mushroom cap, these anchors settle nicely into soft surfaces to hold your boat while you fish, swim, or otherwise relax for a few hours. Mushroom anchors are popular for inflatable boats because they have no sharp points, and they are also easier to stow in small boats due to their compact size. Look for mushroom anchors that are vinyl coated, as these will do less damage to your boat when they get knocked around the hull or deck. Also, make sure it has drain holes. Without drain holes in the mushroom cap, the anchor can be very difficult to pull out of the mud. A 15-pound mushroom anchor can hold a 20-foot boat.
For each anchor type, it is important to consult the manufacturer’s guidelines regarding the right size anchor for your boat. As you can see, the weight needed varies considerably with the different types of hooks.
Keeping your boat in one place can be a lot of fun. It can be your headquarters for water sports, or you can anchor with other boats for swimming and socializing. Having the right anchor will make your time on the water much less stressful, especially if you are planning to spend the night. Once you are able to set it and forget it, you will truly be “hooked” on boating!