If you want to keep your boat in one spot permanently you’ll want to moor it, which means checking out our Boat Mooring Guide to learn how to set up a proper mooring system. But if you want to stop for the night along your way to stay in one place temporarily you’ll want to anchor your boat. Fortunately, anchoring a boat properly is not a complex procedure. Follow these five simple steps, and you’ll get anchoring down pat in no time.
- Choose an appropriate place to anchor.
- Pull into position and wait for forward motion to stop, then lower the anchor.
- Put the boat into reverse and pay out an appropriate amount of scope (anchor line)
- Secure the anchor line.
- Back the boat down a bit to make sure the anchor’s properly set and is not dragging.
Above: Getting your anchor to properly set on the ground underwater is key to making sure your vessel won’t drift while you are anchored. Photo by fergregory on Pond5.
Choosing an Appropriate Place to Anchor
One might think that you could anchor just about anywhere it’s shallow enough for the anchor to touch bottom, but that’s not always the case. Your first consideration is safety — obviously anchoring in the middle of a heavily trafficked channel or a busy harbor, for example, wouldn’t be a wise move. You should also consider bottom type, which is often marked on charts including digital charts in your chartplotter. Rocky or shell bottoms make for difficult anchoring, while muddy or sandy bottoms are more likely to allow for easy anchoring. There are also environmental considerations to take into account. Anchoring on reefs can damage them, and in some areas may even be illegal.
When choosing where to anchor and the type of bottom below, also consider your type of anchor. Different anchors work better or worse on different bottoms and if you choose poorly that anchor may never manage to hold the boat in place. A Danforth anchor, for example, will do a great job on a sandy bottom. But drop that same anchor over oyster shells, and it’s likely to bounce along without ever catching.
Lowering the Anchor
The most important thing to remember about lowering anchor is to do just that — lower it, don’t throw it. Heaving an anchor has no benefit as opposed to simply lowering it over the side, and it can be dangerous. The line can get wrapped around a cleat or fixture and snap back, or worse, it could get tangled around a body part. Instead of throwing it, simply lower the anchor over the side and allow it to drop until it hits bottom. Then, you can begin paying out the appropriate amount of line.
Above: Lowering and raising an anchor should be done with care and deliberation rather than thrown or tossed, or too hastily dropped. Different boats have different anchoring systems onboard, from electric windlass systems to manual chains with or without rollers. Photo via Pond5.
Paying Out Scope – Letting Out Line
When you let out an anchor line, the additional line going beyond the water’s depth is called “scope.” As a general rule of thumb, the more scope you let out the more likely the anchor will hold. In calm weather a scope of four or five feet of line for every foot of water is usually enough to get the job done. So if the water is 10 feet deep, letting out 40 to 50 feet of additional line should do the trick. In choppy waters, a scope of seven to one is more appropriate. And in rough conditions, a scope of 10 to one or even more may be necessary to hold your boat in position. In very rough conditions it’s usually wise to let out every bit of scope possible.
As you let out scope, you may or may not want to back your boat up. Whether it’s necessary depends on the conditions; the strength of the current, and whether or not there’s a breeze. The bottom line? If your boat is moving away from the anchor due to the prevailing conditions, so be it. But if it’s not, shifting into reverse and backing the boat up may be necessary in order to let out enough scope.
Securing the Anchor
Once an appropriate amount of scope is out, you’ll want to secure the anchor. This commonly means cleating the line off on a bow cleat. (Note: always anchor from the bow of the boat, not the stern, because the attachment point will face the waves. Anchoring off the stern can be dangerous, and may result in a swamped boat). However, if the line already has tension on it when you go to secure it, you’ll want to take care. A taunt anchor line can cause injury if your finger or hand gets caught up in it, so it’s a good move to pull out some extra line and wrap it around the cleat while it’s not under tension.
Setting an Anchor
If there’s a good deal of wind or current pushing the boat, once you secure the anchor line the anchor may set itself. In calm conditions, however, it’s wise to use the boat’s power to set the anchor firmly into the bottom. Simply shift into reverse, and give the engine a slight shot of power to help that anchor dig in.
After setting the anchor it’s important to make sure that it isn’t dragging. Look at your chartplotter, and pick out a landmark you can use as a point of reference. Then simply sit back and watch for a few minutes until you’re 100-percent sure the anchor isn’t dragging and the boat isn’t moving.
Bonus Tip: Savvy boaters never entirely trust an anchor. If you’ll be staying aboard set an anchor alarm and check the surroundings regularly to be sure the anchor isn’t dragging. And if you’re jumping off the boat to go swimming or taking a walk on a beach, never go too far and always keep an eye on it. Remember that anchors are meant for holding a boat in place temporarily, not for extended periods of time.