Sea Anchors

Ever since the early days of sail, sailors have faced two opposite challenges: how to make the best of light airs; and how to maintain control when the wind and sea conditions become too great.

All sailors have benefited from evolving technologies that have improved go-fast performance, from types of rig to shapes of hulls to materials used throughout a vessel. But by comparison, a relatively miniscule amount of development (setting aside weather predicting capabilities) has been directed toward technologies to improve the safety of sailing ships in high winds at sea.

What are you saying?

In 1967 Sir Francis Chichester completed the first solo west-to-east circumnavigation via the great capes in 226 days, similar to the typical sailing time of the clipper ships over the same route in their heyday in the 1800s. The technology of the day gave Chichester the extra speed, but he had no better methods of surviving the treacherous conditions along the way than his predecessors.

photo courtesy of Wikipedia commons

“Water Witch” opium clipper
photo courtesy of Wikipedia commons

Gypsy Moth IV photo courtesy BBC Devon

Gypsy Moth IV
photo courtesy BBC Devon

It’s complicated.

To understand the challenge, you have to be able to appreciate the extreme conditions that sailing yachts—as well as any other vessel at sea—can face anywhere in the world. It is usually the large seas that the winds can create that are the biggest hazard to ships of all kinds.

photo courtesy of Patrice Dufour

photo courtesy of Patrice Dufour

This short video gives you an idea what it’s like to be on a sailboat in thirty-five to forty-five knot winds and moderate seas. The size of the waves depends a lot on the “fetch”, or the distance across the water that the wind blows to create the waves—more fetch equals bigger waves. A classic example is the Roaring Forties, the strong winds that circulate around the globe, unobstructed, in the high latitudes of the southern hemisphere and create monster waves.

photo courtesy of Jason Conlon

photo courtesy of Jason Conlon

For centuries, sailing ships caught in storms have used the same strategy. First, reduce the amount of sail to reduce the strain on the vessel’s masts and rigging. Then, in extreme conditions, run before the wind, trailing “warps”—lengths of rope—to slow the vessel to prevent surfing and the risk of broaching. When rigging was damaged, they sometimes dragged the broken spars, sails, and lines with the same effect. Sometimes the strategy worked; sometimes it didn’t.

Modern yachts have changed a lot since the days of the tea clippers. Design and performance differ greatly, and, as before, there is no single solution to the complex problem of keeping sailboats safe in high winds and seas. But it is perhaps because the number of offshore vessels is so small that the technology hasn’t advanced further. And many of the high-profile racers that seek innovation and lead cutting edge design aren’t interested in slowing down!

So what are our options?

photo courtesy of John Boyer

photo courtesy of John Boyer

There are two situations that are sometimes confused in discussing heavy weather sailing, so it’s best that we clear that up right now. The first situation is when a sailor wants to carry on safely in high winds and seas. The second is when a sailor wants to stop in order to rest, make repairs, hold a position to avoid a hazard, or simply wait until the conditions improve. In general, a sailor can use a small sea anchor or drogue in the first case to slow a vessel, and a large one in the second case to stop it (more or less).

Now, many of you will say that a sailboat can simply heave to in order to rest. Yes, that is true if there is plenty of sea room. We three have all done that in various vessels in a variety of conditions. But if there is not adequate sea room, the sailboat’s leeway may take it into danger. Also, some sailboat designs simply won’t allow them to heave to or lie ahull. And for those that do, some naturally lie broadside to the waves, with the risk of capsizing in adverse conditions.

photo courtesy of "Editor A"

photo courtesy of “Editor A”

There are detailed technical works that analyze and explain the dynamics of weather and discuss heavy weather seamanship. One that we have relied on is Oceanography and Seamanship, by William G. Van Dorn, first published in 1974 and republished in 1993. In that book, Van Dorn suggests using a parachute as a sea anchor “available on the surplus market for a few dollars.” He goes on to develop a formula and graph to predict approximate drift rates for different sized ‘chutes.

But that’s all theoretical. Van Dorn’s book is also good for its practical advice. He explains that, whatever sea anchor you may choose to use,

“A parachute drogue is best rigged beforehand on a calm day, and stowed in a small bag, since anyone who has seen a spinnaker get out of control can visualize what will happen if a parachute gets loose in a high wind.

“Like storm anchoring, drogue anchoring should be practiced in moderate weather, until you have ironed out the kinks, and feel sure that all steps can be accomplished smoothly under duress.”

That’s fine, but you’ll have to show me.

Today, more modern devices are available to cruising sailors, fishermen, and small commercial vessels of all types. Most are based on the original parachute concept. This very short video,

photo courtesy of Alexander Rist

photo courtesy of Alexander Rist

taken from a sailboat forty miles off the Patagonia coast, shows the effect of using a parachute anchor in sixty knot winds (almost seventy miles per hour or over 110 kilometers per hour). The skipper reported six meter (twenty foot) seas. They can be much larger. Having seen these conditions, it should be easy to appreciate Van Dorn’s advice to practice before you need to use a sea anchor. Here’s another video, prepared by the maker of one brand of sea anchor, of someone doing just that.

And here is a twenty-minute video, prepared by the same sea anchor manufacturer, that tests seven popular kinds of sea anchors and different weighting devices to see how effective they are. None of us has ever had to use a sea anchor, so we can’t give you any advice based on our personal experience, and we don’t endorse any of the sea anchors shown in the videos.

How do you choose?

photo courtesy of Gavin Spencer

photo courtesy of Gavin Spencer

The best thing you can do is educate yourself about how to sail in heavy weather and what options are suitable for your particular vessel. Remember, every vessel responds differently. Even two identical vessels in the same conditions can act differently, depending on how gear and provisions are stowed, the number of crew aboard, and the rigging and set of the sails.

There are many sources of information, including books, videos, training courses, and testimonials by people who have been out there and done it. Here is one video in a series by the Maryland School of Sailing and Seamanship that we found in a quick search of the internet. You may find others as well.

photo courtesy of Daniel Jacob Horine

photo courtesy of Daniel Jacob Horine

If you think that you want to take a sea anchor on your next offshore passage and can’t decide between two kinds, we suggest you consider taking both. The additional cost will seem unimportant if you ever find yourself in the situation where you need it. Remember, “there are old sailors and bold sailors, but no old, bold sailors.”

featured image courtesy of Bartek Wilk
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