Stu Hochron is founder and author of the truly excellent sailing online newsletter News From The Bow. Adam
Why Bother to Anchor?
Every boater reaches a point when he/she either chooses to anchor, or when his/her vessel’s safety depends on proper anchoring.
As with everything in life, however, the benefits of anchoring “out” come at some cost, including:
- taking the time to understand how to anchor
- preparing and maintaining your rode/chain/anchor system
- in the case of chain and deep anchorages, possibly needing a windless
- the general requirement of a sound dinghy for visits ashore
- having to deal with other anchored boats
Best Anchoring Reference
Before going any further, let me refer you what I consider to be the best available reference on anchoring, “”Happy Hooking”, by Alex and Daria Blackwell, Published 2008 by White Seahorse, Inc. The Blackwells detail all aspects of anchoring in this inexpensive paperback volume, and include the newest technology in anchors and technique. If you read this book before you head out, and you will be better prepared for any anchoring challenge.
Choosing the Right Anchor for your Boat
If you are serious about staying overnight at anchor, then you need to choose the best spot to lay the hook, understand upcoming weather and tide conditions, be aware of the type of bottom your anchor will encounter, avoid chafe, have a well maintained anchor rode or chain, and prepare an anchor watch plan. While all of the above is important, your life will be made immeasurably easier if you have a great anchor to do the job.
Happy Hooking contains an excellent review of all standard anchor types, including those invented more recently. Having used Fluke, Plow, Claw and Spade type anchors myself, I am convinced that, for general use in the Northeast U.S., a spade type anchor is best. These anchors have sharp points to penetrate hard bottom and are designed to dig deep under increasing loads. Two new spade anchors excel. They are the Rocna and the Manson Supreme anchors (see photo of Rocna anchor). These two anchors look similar, and to the best of my knowledge perform similarly. They have a roll bar and are weighted such that the sharp point of the anchor achieves its best-set position soon after hitting the bottom. This minimizes drag before the anchor sets.
The only objectively measured difference between the Rocna and the Manson is the ability to set with short scope (2:1) in rocky conditions, where the Manson Supreme outperformed the Rocna in a recent test by Practical Sailor. Both have trip line attachment points. The Manson Supreme also has a “rock slot” which enables the shackle to ride forward and have the chain act as its own trip line in rock or coral (more on trip lines in an upcoming issue of NFTB). The rock slot arrangement seems ill suited for anchoring in all but predictably steady wind and current conditions. The Rocna and Manson Supreme seem like near equivalents, except for Manson’s reported short scope setting ability and its rock slot.
The greatest disadvantage in using a Rocna or Manson anchor is also its greatest advantage…its ability to stay stuck. I have been forced to change techniques when weighing my Rocna anchor, as it digs deeply, brings considerable amounts of bottom to the surface, and leaves a hole where it was set. I need to raise the anchor chain to a nearly vertical position and motor forward, or in circles, to break the Rocna free. I also routinely set a trip line in case these techniques fail. Once the anchor is on the surface, and if conditions allow, I then motor slowly in reverse while the Rocna remains just below the water to wash debris off the anchor. A raw water deck wash is also very useful to finish the “de-mudding” job if you are using a Rocna or Manson Supreme anchor on mud bottoms.
Recently I dove on my Rocna anchor while anchored in Martha’s Vineyard. To my great surprise the anchor was nowhere to be found. Its chain disappeared into a soft bottom, followed by at more than three feet of its trip line (my trip line float, set at four feet above the anchor, was just visible). No wonder these anchors hold and come up attached to former bottom.
The choice of which type of second anchor to keep aboard will depend on your needs and your cruising grounds. A Delta fluke type anchor is an excellent choice for general conditions, as is a Bruce claw type anchor. Both set well in differing conditions, however may drag under extreme wind loads.
Your anchor’s size will depend on your boat’s size and type, and should be carefully chosen by referring to manufacturer’s recommendations. My only advice is, if your recommended anchor size is close to the next higher recommended size, then choose the larger anchor. The benefit of peace of mind will far outweigh the incremental increased cost of the larger anchor.
Your Anchoring System
One definition will be helpful here. While most parts of an anchoring system are self explanatory, the term “rode” begs clarification. Webster’s Dictionary defines anchor “rode” as a rope or a chain used to attach an anchor to a boat.
The water depth of your cruising grounds will dictate the length requirements for your anchor rode. At the very least you must carry enough rode to maintain a 7:1 anchor scope at the highest tide of your deepest anchorage.
The choice of whether your anchor should be attached to your boat with all rope, all chain, or a combination of the two, depends on (i) the type of bottom (ii) your vigilance to monitor chafe where anchor rode meets boat (iii) the type and size of your anchor rode locker and (iv) whether or not your boat has a windlass on the bow. Lots of chain is great insurance against chafe from bottom rocks or coral, and in heavy conditions, but is heavy work to raise without a windlass. At the very least a short section of chain attached to the anchor will assist with setting if your anchor rode is all rope. Choose anchor rope and chain dimensions per manufacturer’ recommendations for your boat.
Anchor “swivels”, which attach between an anchor and chain, are marketed as tools to prevent anchor line or chain twist. Some experts strongly recommend these, while others see them as weak links in the anchor system. If you have a problem with twisting (or untwisting) anchor rope, and you choose to use one of these swivels, at least purchase a high quality stainless swivel with an excellent reputation. Otherwise you might plan to anchor after a long trip only to find that your anchor is resting at the bottom, far, far away.
In order to minimize stress on bow cleats anchor, your anchor rode should “stretch” under load. Nylon rode alone stretches nicely, however an all chain rode requires the addition of a nylon rope “snubber”, or a system designed to weigh down the center of the chain rode, to permit the rode to stretch (see photos of anchor snubber). Nylon rope snubbers are easy to store and to use, and should be a routine part of anchoring with all chain rode. A 10 to 50 foot nylon rope snubber is usually enough to provide a gentler ride, and some protection, when riding on an all chain rode in significant conditions.
Choosing Your Anchoring Location
Check your charts well in advance of arriving at your anchorage. Obtain as much local knowledge as possible from fellow mariners before you arrive. Refer to a cruising guide for details of your destination’s holding ground and recommended anchorage locations. For the Northeast, I suggest carrying a copy of The Cruising Guide to the New England Coast by Duncan, Fenn and Ware (W.W. Norton & Co.), which, unlike many newer cruising guides, includes detailed anchorage information. View overhead photographs (available in many chart kits, on some chart plotters and in many cruising guides) of the anchorage before arrival. Be aware of the placement of any permanent moorings, which may make the choice of an anchoring location more challenging. Know the tidal range and predicted tide times at your anchorage.
NOAA charts will tell you both the mean low water depth and the bottom type of your prospective anchorage. Check the chart “key’ for bottom type descriptions (“s” for soft, “h” for hard, etc.) and avoid hard bottoms and restricted areas. Avoid well marked “cable areas”, as hooking onto one of these underwater cables might cause you to trade leaving your anchor and rode behind in return for a departure.
The Proper Method to Drop Anchor
Once you arrive, circle the area around you planned anchorage to be certain there are no underwater objects that could surprise you as you swing with the wind or current. If wind or current is predicted to change, then factor these into account and pick a spot in the lee of land that will protect you from wind. Unless space and conditions mandate that you anchor nearby other vessels, avoid the ‘herding effect” of anchoring nearby other boats. If you must be close to another vessel(s), drop your anchor behind another anchored boat and pay out approximately the same amount to rode that he/she is using. You can either guestimate your neighbor’s scope by the angle his/her rode enters the water, or simply ask your neighbor. Remember, the first boat to anchor sets the standard for all boats to follow with regard to scope.
Refer to your depth meter to determine how much rode is required. Remember, your scope should be relative to high tide, so know the times of high and low tide, and the range of tide at your anchorage.
Lower (never throw) your anchor once your boat is at a full stop. Pay out enough anchor rode to approximate 2.5 scope as you drift or motor back slowly. Then, cleat your rode. The anchor should set as your bow slowly drifts upwind against the pulling rode. Pay out the remaining rode to achieve the desired scope. If you are using chain rode, now is the time to place your nylon snubber on the chain.
In order to be assured of a good set, back down on the anchor at low power (under 1000 rpm) while someone on the bow has his or her hand on the rope rode or snubber. Dragging of the anchor will be identified by an erratic pulling, or jumping feeling transmitted through the rode. Sometimes allowing the anchor rode to drag for 10-25 feet will cause it to set. If no set occurs you will need to weigh anchor and re-set at another location. Once your anchor is properly set it is time to relax and enjoy your new home.
If your anchored boat comes too close to its neighbor, the unburdened vessel (the boat that is not required to move) is the boat that arrived first. Therefore, have a “Plan B” in case you have miscalculated and need to move after anchoring. As a courtesy to neighbors, please do not run generators and keep noise to a minimum after sunset.
Setting an Anchor Watch
Joshua Slocum on his boat Spray used several methods to alert him that his anchor was dragging. These included attaching light lines to the rode that would part under load and wake him, and determination to rise every few hours to visually check his location. Today’s electronics make setting an anchor watch easier and more reliable. Suffice it to say, most GPS systems include anchor watch alarms. Once set to the appropriate distance, taking into account maximum distance the boat could travel in circles without the anchor dragging, these devices will alert a light sleeping skipper to possible trouble. Electronic anchor alarms do not, however, take the place of vigilance in setting your anchor, awareness of your location relative to non-moving objects to permit visual checks of position, knowledge of changing weather conditions, and preparation of a plan to weigh anchor and move if this become necessary.
Preparing to Weigh Anchor
Once your boat is prepared in the usual manner to be underway, bring the rode up to a vertical position by hand or with the aid of a windlass. Use your engine to move the boat forward if necessary. Be careful not to overload the windlass if the wind or current does not permit the boat to move easily forward as rode is collected.. It is not advisable to use a windlass to do anything but raise unloaded anchor rode. Windlasses are designed to gather chain from the bottom, not to pull boats through the water against wind and/or current. High pressures on the windlass may damage the devise. If bringing the rode to a near vertical position does not “break” the anchor free, then use one of the following methods to raise the anchor:
- Let out enough rode to fall back, and then slowly motor forward until you are nearly above the anchor. Immediately cleat the rode and allow the boat to continue forward. This will usually solve the problem of a “stuck” anchor. Limit your speed to avoid damaging the hull or propeller with anchor rode or anchor.
- Use your “trip line” (hopefully placed on the anchor before the problem arises). More on the use of trip lines in another article.
- With the rode taught above the anchor, move your crew to the boat’s stern to raise the bow. This may help depending on the weight of boat and crew.
- Enlist a neighboring powerboat to run a few circles around you. The wake created may lift the bow and break the anchor free.
- Consider diving to evaluate the reason(s) why the anchor is not breaking free if you are prepared to do so, and if the depth and water conditions allow.
- If you are in an area of considerable tide variation, and you are lucky enough to be at low tide, tighten the rode and wait. You will be free in a few hours unless you anchor is attached to an underwater cable or immovable object.
If all of the above fails, tie a fender, labeled with your boats name and contact information, to the rode and leave it as you depart. Perhaps you can return another day to collect the anchor under different circumstances.
We hope this article will help you enjoy the peace and beauty of your next anchorage. It attempts to relay anchoring information that has been most valuable to the editors over the years, and which we believe will be most useful to the reader. Those interested in learning more about the subject are referred to Happy Hooking, as referred to above.
If you recommend other anchoring techniques, or have valuable anchoring stories that you feel will be useful to other readers, please contact us.