Learning how to anchor a boat is a basic seamanship skill that every boater should master, even if you don't anticipate anchoring very often. Understanding how to set the anchor and retrieve an anchor is critical -an anchor can hold your boat in place in a secluded cove for a few hours of swimming or an overnight stay, but it's also an essential piece of safety gear.
If your boat engine fails, a well-set anchor will keep wind or current from drifting your disabled boat onto a shoal or ashore, where it could be damaged.
We’ll just cover the basics here, and remember, a good seamanship guide or course will go into much more valuable detail.
How to Anchor a Boat
- Determine the water depth where you want to drop anchor.
- Calculate the correct amount of anchor scope (a 7:1 ratio is recommended).
- Lower the anchor and let out enough scope, then secure the rope to a bow cleat.
- Ensure there is no drag - use landmarks or onboard electronics to measure movement.
- If needed, reset the anchor.
- To retrieve the anchor, slowly motor toward the anchor while pulling in the rope.
- Remember, never tie off an anchor to the stern of a boat.
Types of Anchors
The most-common pleasure boat anchor type are the fluke (often called a Danforth), and the plow or scoop anchor.
- The fluke anchor is popular for small to medium size boats because it folds flat and so is easy to store, and is lightweight and easy to handle. It offers excellent holding power in a sand or muddy bottom, but is not as effective in a rocky bottom.
- The plow-style anchor is more common on heavier boats and holds well in most bottom conditions, and also usually resets itself if the wind shifts. It does not fold and is usually heavier than the fluke anchor, and so is best-suited to boats with a bow roller and windlass, rather than an anchor locker. The anchor is connected to the boat with the rode; on most family powerboats the rode includes a length of chain at the anchor end and nylon line (rope) from the chain to the boat.
Use anchor manufacturer guidance to determine which size anchor is appropriate for your boat.
Setting an Anchor
- If possible first determine the water depth where you want to drop anchor, using a depth finder if one is on the boat. Water depth will determine the correct amount of anchor scope required; scope is the ratio of the length of the anchor rode you will want to pay out to the depth of the water.
- A scope ratio of 7:1 (seven feet of scope to one foot of water depth) is usually recommended, when there is room. If, for example, you know the water depth is 10 feet, motor into the wind or current about 70 feet beyond the point where you want to the boat to lie on anchor, and drop the anchor.
- Then, either let the wind or current carry you back 70 feet, or move the boat in reverse that distance if there is no wind or current.
- When you’ve let out enough scope, secure the rode to a bow cleat.
- Then apply some power in reverse to set the anchor in the bottom.
No Anchor Drag
You want to make sure that the anchor is set and not dragging on the bottom. You can sight on two landmarks on shore, or use electronics such as GPS, a chart plotter, or a depth finder to sound an alarm if the boat is moving.
If the wind, current or tide changes and causes the boat to swing over the anchor, it may reset itself on the bottom. If it does not you’ll need to re-set the anchor. It’s important to stay vigilant at all times when anchored.
Retrieving the Anchor
- To raise anchor, slowly motor towards the anchor while pulling in the rode.
- When you are directly over the anchor it should pull free. If it’s stuck, first try slowly turning the boat in a large circle to change the direction of pull on the rope.
- Another method is to pull up rode until the boat is directly over the anchor, and then give the line a turn around a cleat.
- Pull it taut as the bow dips in the bottom of a wave, and when the next wave lifts the boat it may break the anchor free.
Additional Anchoring Tips
Here a few additional factors to keep in mind when anchoring a boat:
- Never tie off an anchor to the stern of a boat, or try to pull up a stuck anchor by pulling with the engine after securing the rode to a stern cleat.
- You may actually pull the stern low enough to swamp the boat—water may come over the stern and fill the boat—resulting in a very dangerous situation.
- If you can’t release a stuck anchor, it’s best to simply cut the line and replace the anchor.