In earlier columns, we looked at how ground tackle works, reviewed anchoring methods and discussed considerations when choosing an anchorage. But what if your anchor starts to drag? How would you know? What would you do?
Preparing for an anchor to drag actually begins long before it happens. The first thing to do upon settling into an anchorage is to establish your position. This is the baseline against which you will measure any change. The most venerable method is to take visual anchor bearings, usually three. Charted objects are not necessary; you are less interested in your latitude and longitude than you are in whether your position is changing. A tree, house or flagpole will suffice, though not a dog unless it is a very good dog. At night, shore lights can be used for bearings.
Bearings should have a spread between them—at least 45 degrees—with one on the beam if possible. Avoid bearings that are dead ahead or dead astern, as they don’t provide any indication if you are dragging anchor. Bearings that are reciprocal to one another are duplicative and therefore provide less information.
Radar ranges are also good for monitoring your position, especially if the shoreline provides a distinctive echo that doesn’t change radically with the tide. Unlike bearings, radar ranges are most useful dead ahead or astern. If you have an echo ahead or astern, set up a variable range marker (VRM) tangent to it. If you are dragging away from an echo that is ahead, it will be easy to detect the VRM ring pulling away from it. Likewise, if you are dragging toward a radar reference astern, the VRM ring will visibly move into the echo. Radar bearings can augment visual bearings, with the advantage of being very effective in the absence of visibility.
It is normal for the boat to wander around the anchor with changes in breeze and tide. You need to allow for this when checking your position. Log the depth at the time of anchoring. If the depth changes in ways that cannot be explained by the tide, then you may be dragging anchor. In anchorages with a uniform depth, soundings won’t be much help, but depth is often useful for correlating your position with other data.
Naturally, you can jot down your latitude and longitude from a GPS, and if you have a chartplotter, you can monitor position that way. Many chartplotters have an alarm function, as do radars and depthsounders. Changes of position due to wind and current may trigger those alarms. An alarm doesn’t necessarily mean you are dragging, but you might want to check.
For any number of reasons—insufficient scope, poor holding, severe weather, inadequate ground tackle—sometimes the anchor just won’t hold. The easiest response to dragging anchor is to pay out more rode (add scope). This increases the horizontal part of the strain, a tactic that is often enough to re-bury the anchor’s flukes. To increase scope, you must have rode in reserve and room around the boat to accommodate a larger swinging circle. If you’ve failed to appraise the anchorage in the first place, you may not have those options available.
Another response to dragging is to let go a second anchor, which is a good reason for having one. Pay out the second rode until both anchors share the load; if one anchor is doing all the work, it will continue to drag. It is not difficult to imagine a situation where you run out of rode on the first anchor before the second one has become effective. Having enough rode in reserve on the first anchor to match tension with the second anchor goes back to choosing an anchorage that leaves you with options.
Finally, if your anchor(s) simply won’t hold, you may have to pick up and start all over, but it can be hard to re-set anchors when the flying fish are already hitting the fan. You may simply have to head for open water and ride it out, or find a better spot to anchor.
If strong weather is expected, it may be best to put down two anchors at the outset, while you have more control over the situation. In this scenario, the ideal angle between the anchors is 60 degrees. There are a number of ways for setting two anchors, but they all involve dropping one, maneuvering away from it while paying out rode, and then dropping the second one. Once they are both down, take up the first rode until the strain on both anchors is more or less equal. There is a lot of eyeballing involved with this maneuver, but that is the general idea.
On rare occasions, it may be necessary to bid your ground tackle goodbye on a temporary basis. Perhaps you are dragging anchor so fast that there isn’t time to recover before the boat goes into the shallows. Or, perhaps someone else is dragging anchor down onto you, making it impossible for you to weigh anchor without colliding.
This is the main reason why it is a shibboleth of seamanship always to fasten the anchor rode to the boat in such a way that it can be detached in an emergency, even under tension. The bitter end should be fastened to a strong point in the chain locker that is accessible in all situations without risk to life and limb.
In a true emergency, fiber rode can be cut, but a chain is not so simple. One way of handling chain is to lash the last link to a strong point using multiple passes of a strong synthetic line. The lashing can approximate the strength of the chain itself, but it can still be cut away in a pinch. Some types of hardware, such as a pelican hook, are designed to be released under load and may also do the job.
If jettisoning ground tackle is a possibility, then we should be equally prepared to retrieve the tackle when conditions permit—another reason to log your position upon anchoring. To reclaim your ground tackle, you must buoy the chain before releasing it. Pass one end of a line outboard of everything (lifelines, stanchions, rigging) and fasten it to the rode. Tie the other end to something buoyant. Make sure the line is long enough so that the buoy reaches the surface at high tide. Get everyone clear of any possible entanglement and let ’er rip. When you come back, snag the buoy with a boathook. Haul back on the tether until you get to the rode. Haul back on the rode until you get to the anchor. Then give yourself a big pat on the back for your foresight—and remember to reattach the rode.
This article originally appeared in the June 2019 issue.