Pro/Con - Should you anchor from the stern in a storm? - Soundings Online

Pro/Con - Should you anchor from the stern in a storm?

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Con - Stern anchoring? Not upwind of me, please

Con - Stern anchoring? Not upwind of me, please

The technique described by Donald Jordan reflects a great deal of thought, study and effort in finding a better way for boats to survive storms at anchor or on a mooring. Sailing back and forth on an anchor or mooring line, from one side to another, and jerking up short on the end of the swing produces stress on gear and can result in serious chafing and gear failure, especially if proper preparations haven’t been made.

But while stern mooring/anchoring may in theory be the best solution for a few boats in limited circumstances, it isn’t, in my opinion, the best method for most boats and most circumstances, especially storms and hurricanes. And if anyone thinks their boat is one of those few, I hope and pray that they don’t test this theory upwind of me in a storm, and that their insurance carrier — always ready to raise premiums because of losses — isn’t the same as mine.

The underlying rationale for this technique is premised heavily upon the assumed behavior of boats with a cutaway forefoot, fin keel, spade rudder and single mast forward of the beam. Many of these do jerk short at the end of each swing as they careen first in one direction and then another. While this can be a contributing factor to gear failure, there’s much more to the story. Further, many boats don’t have these physical characteristics, and some that do don’t necessarily exhibit the severe behavior described.

There are many reasons why we shouldn’t anchor from the stern. Most boats are designed and built to present the bow to seas and wind. Presenting the “pointy” end to the oncoming storm not only uses the design of the hull to present less resistance to seas and wind (and thus to lessen stress), but also uses the design and shape of the superstructure, which is usually designed to best deal with winds coming from the bow. Presenting the broader stern can create considerably more resistance to wind and seas and, thus, considerably more strain on gear.

Still other factors should be considered. Typically the after portion of both power- and sailboats has a relatively broad entrance to the cabin, a flat surface at the aft end of the cabin, and often a large opening area with glass or doors. Also, many boats have large, open cockpits at the stern. Boarding seas and high wind from this end can cause serious problems.

The assumption that waves in a hurricane harbor will only be 4 to 6 feet isn’t necessarily valid. They can be much higher, and their speed and other characteristics can make them much more damaging than what we normally experience with 4- to 6-foot seas. (And 4- to 6-foot seas are bad enough as it is.) It’s true that stern drogues have been of great benefit to many in storms at sea. But in these situations the boat (usually a sailboat) is moving with the wind and waves in open sea, pulling the drogue along behind it, rather than being held stationary against steep, pummeling chop.

A boat anchored by the stern also has an increased risk of damage to rudders, their shafts, and their shaft logs. The likelihood of rudder damage depends on many things, including location of the rudder, the tendency of the stern section to expose the rudder to the sea, and the type of rudder. For example, the spade rudder is one of the characteristics noted as being typical of boats that could most benefit from being anchored or moored from the stern. This is a large, flat plane, usually close to the transom and supported only by a single shaft that pierces the bottom. Short, steep chop slamming into a rudder as the boat’s stern rises could break it off or at least damage its shaft log, causing catastrophic leaking. And for the reasons and with the same results noted in the following paragraph, the anchor line could become snagged in the rudder.

Depending upon the type of sea in the harbor, current, and the hull configuration and location of the propeller, there’s risk of the anchor/mooring line fouling on the prop and ultimately causing a breach in the hull if the line isn’t cut first. This could occur as the boat plunges, as it is pulled forward when the rode recoils, or as it responds to a sudden wind shift (common with cyclonic storms) or cross sea. I saw this happen recently on a well-designed boat anchored by the stern in moderate weather. Even if the likelihood of this happening is deemed low, the certainty of a sinking should it happen is enough to warrant avoidance of that risk.

There are many things we can do to significantly reduce yawing and jerking without anchoring from the stern. The effectiveness of any one or combination of these depends upon the boat, the skill and diligence of the owner in storm preparation, and other circumstances. Following are several examples to consider.

Draping chain between the bow roller and the chain hook at the end of the snubbing line can significantly reduce yawing and jerking short. The chain loop should arc down deeply enough so that there’s a large amount of chain loop dragging through the water, though it should clear the bottom. As the boat tries to veer off the wind the chain loop’s drag can inhibit the motion significantly.

Use of an all-chain rode also reduces yawing because the chain must drag across the bottom. I’ve been under water observing anchor chain on soft sand during veering gusts to around 50 knots (not hurricane force, but strong enough to indicate a pattern of behavior) and seen that the chain hardly moved sideways across the bottom. I should note that if the wind is strong enough, the chain will straighten. But the chain loop as described above still helps even if the chain has straightened.

A well-rigged nylon snubbing line, properly sized for the conditions, is critical with all-chain rodes because it increases elasticity both as a result of its own properties and because it allows deployment of the chain loop. An all-nylon rode can significantly increase yawing because it is so light and can be dragged easily through the water. Some also report that the use of heavy steel wire (again with snubbing line) on a muddy bottom can, by digging into the mud, help to lessen the swing arc, as well as assist the anchor in digging in.

Some boats ride much better, and with less swing by using a V bridle from both sides of the bow, leading to the rode. Some use this concept with two anchors. Although there are liabilities to using two anchors on an everyday basis, many prefer to do so in storm conditions. When these are set so that the boat is at the apex of the V of the rodes form, many boats will lie more steadily into the wind.

Whatever form of anchoring is used, well-rigged chaffing gear is critical and has been used successfully for centuries. While this will wear during the storm, enough good chafing material, well secured, can prevent the rode from parting.

I’ve given my opinion based upon my experiences. Different boats and different circumstances require different anchoring techniques, and each skipper should know and do what works best for his or her boat and the circumstances of the moment. We’ve spent many a fearful day and night in storm and hurricane conditions clinging to a hook in the bottom, fearful not so much of our gear and holding but much more so of boats upwind of us that were obviously poorly prepared. It’s great to know that there are people like Donald Jordan who care about this aspect of seamanship. However, I have to say that if I saw a boat anchoring stern-first upwind of me with oncoming weather, I’d move to another part of the harbor … if there was still time left.

Tom Neale is Soundings’ technical editor, and has lived aboard and cruised full time since 1979.