Setting Two Anchors
There are situations where ‘just’ one anchor may not suffice. The first that always comes to mind is a storm or heavy wind, when you simply need more holding power. As we discussed in our book Happy Hooking – the Art of Anchoring, your primary anchor should be sized to provide adequate holding in most any conditions. If you feel it is not big enough or the right type, then your first consideration should be upgrading or changing it. Having said that, although we are fairly confident that our anchors are correctly (over-) sized for our boat, we do routinely set a second anchor when we know there is a big blow coming. It gives us tremendous peace of mind. In any case, in a storm situation, your best option is to seek safe harbor so as not be subjected to strong winds and rough seas.
Other times when you might consider two anchors include tight anchorages, poor holding (like very soft soupy mud), shifting currents, prevailing swell, the narrow edge of a channel, wishing to position your boat precisely over a noted fishing spot, and so on. Just like there are many types of anchors, there are many ways to deploy them if and when you need them.
You might wish to consider setting two anchors in series – one behind the other, which is known as tandem anchoring. U.S. Navy tests show the use of tandem anchors increases total holding power by as much as 30 percent over the same two anchors if deployed separately.
To do this, the primary anchor must have an eye or hole at the crown through which to attach the rode to the secondary anchor. The Rocna and Buegel anchors have such a dedicated attachment point. Do not use the hole or connection point for the trip line, which most anchors have, as this may cause the primary anchor to roll and unset during a wind shift.
If the anchors should drag or plow through the bottom, then the secondary anchor will find poor holding in the disturbed seafloor created by the primary. Using a plough type anchor for a tandem rig is thus ill advised.
Attach a length of chain rode, that is at least as long as your boat, to the tandem anchor connection point with a sturdy shackle – you should only use chain for this. To make later retrieval of the two anchors easier, attach one end of a floating retrieval rope to the shank of the first anchor and the other end to the shank of the second anchor.
We recently came across the Wemar tandem anchor, which we are looking forward to trying out in the coming months. Their system is in essence two nested anchors, where the secondary is deployed first. Then a chain lock in the shank of the primary is engaged. Then the primary anchor is deployed. Retrieval is the same process, only in reverse.
What not to do
We have sometimes heard the suggestion of deploying two anchors on two rodes in series with a secondary backup anchor upwind of the primary in case this one drags. This is not a good idea. If the downwind primary does drag, then the secondary will be lined up with the furrow of disturbed ground the primary created.
If you think your anchor might drag – replace it.
Setting Opposing Anchors
If you need to keep your boat in one place, even if the wind or current changes direction, then you may need to set two or more opposing anchors.
Bahamian mooring – Two anchors from the bow
The Bahamian Moor is essentially the same as the V configuration taken to its extreme – setting the two anchors 180 degrees apart. It allows your boat to swing pointing into the wind or current – whichever exerts the greater force on your boat and wherever it comes from at a given time. It can thus be very useful in an anchorage with a strong reversing tidal flow.
This method of anchoring also minimizes your swing radius. It is a configuration you may consider in a tight anchorage, provided, of course, that the other boats do the same. It can be useful also when anchoring close to boats on moorings where their swing radius is quite small, although anchoring in a mooring field is generally not recommended.
Bow and stern configuration
The bow and stern configuration maintains the position of your boat very tightly. Your boat will not swing into the wind or current and it should only be used when really needed – such as for anchoring at the very edge of a tight channel when you do not want to swing at all or anchoring off a beach when there is a swell coming in off the ocean causing your vessel to rock side to side.
In European marinas and many other places docking involves anchoring. Many marinas or docks require stern or bow to tie-ups to save space. The so-called Med mooring is basically a variation on the bow and stern configuration.
First and foremost, it is important to be prepared. You will need dock lines aft (or forward if going bow in) and fenders all around. Stop your boat in line with the slot you have previously chosen. Remember to allow for prop walk if your boat does this, and also allow for the wind or current to potentially push you to one side. Try to position your anchor location a bit upwind to help stabilize your approach. Then deploy your anchor, and back into the slip or slot while letting out your rode. (You may also deploy a stern anchor and go in bow first.)
As you come in to the dock pass your lines ashore, or preferably to your new neighbors to bring ashore while steering you in. Once the anchor and dock lines are deployed, firm up on the anchor rode and deploy spring lines to keep the boat aligned fore and aft.
Alex and Daria Blackwell are the authors of “Happy Hooking - The Art of Anchoring.” It covers every aspect of anchors and anchoring in a fun and easy to read format with lots of photos and illustrations. It is available from good chandleries, Amazon and on our publishing website.
For more information on this subject or on anchoring in general, please see our book:
Coastal Boating (Reg. in Ireland No. 443222) is a division of Knowledge Clinic Ltd.
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