What are all these wind shifts about and how can cruisers take advantage? (published June 2013)
Every sailor knows the wind is never static. We know this because we can see it on the water and feel it on our face. Constantly moving, the wind can shift over a matter of seconds or days and because the wind shifts so frequently—and being sailors—we have to name all the different types of shifts that we encounter. With terms such as header, lift, veering, backing, lull, puff and gust used to describe how the wind shifts in both direction and velocity, the big question is: what are all these shifts and how do they apply to a cruising sailor?
When most sailors think of reading and using wind shifts they envision serious racers hell bent on winning constantly looking at the water, shouting about what the wind is going to do next. While this is a bit dramatic, but not far fetched, the fact of the matter is, they are trying to use the wind to get to a mark or start/finish line as fast as they can.
Experienced cruisers do this too, but instead of finish lines or windward marks as a destination, they have picturesque anchorages. While it is true that cruising sailors tend to use the smaller shifts less often than the larger ones, both still matter when out for a leisurely day sail or making a multi-day passage.
We think about wind shifts in two different ways: directional wind shifts are based on the compass and our boat; and velocity shifts are based on changes in wind strength. Wind shifts can be a function of localized or broad weather patterns; geographic features like hills, trees or buildings, and can be seen by looking at ripples and waves on the water. Here are the basics of wind shifts and how cruising sailors can enhance their performance by using them to their advantage.
DIRECTIONAL WIND SHIFTS
There are four terms used to describe shifts in wind direction: header, lift, veering and backing. These terms are often misused when referenced by cruising sailors, which is understandable as they are easy to confuse, but there are major distinctions between them.
Veering and backing are terms used purely to describe how the wind is shifting either clockwise or counterclockwise around the various compass points. A veering (or clocking) wind is a clockwise shift and a backing wind is a counterclockwise shift. So, if the wind is out of the north and it shifts to the northeast—that is veering. If it shifts to the northwest—that is backing. It does not matter what tack your boat is on, what heading you are on, or what direction the wind is coming from, veering and backing are always clockwise and counterclockwise.
Sailors primarily use the terms veering and backing to describe large shifts or trends in the wind. As a front passes in the northern hemisphere you can expect the winds to veer initially and then back once the front has gone through. In general, if you know the wind is expected to veer or back while on a passage you can plan your route accordingly.
Once, while delivering a boat north up the west coast of Florida, the wind was out of the north with an expected veer to happen overnight to the northeast then east. Knowing that, I decided we should sail towards the shift close hauled on a port tack. When the shift happened, we tacked over to starboard and were then on a beam reach to our final destination. Had we done the opposite and started out close hauled on a starboard tack, when the wind veered we would have had to beat back towards our destination.
On the other hand, headers and lifts are purely described relative to the bow and stern of the boat. A header (or knock) is a wind shift towards the bow. I teach students to remember headers by name, a header is coming from “ahead” of you, and you can’t sail directly into the wind. Thus, if you are sailing close hauled and get headed, the sails may luff, which will then force you to fall off in order to maintain speed. A lift is just the opposite. It is a wind shift towards the stern that will allow you to come up closer to the wind or, will “lift” you up.
The confusion between the four terms is that a header or lift can be a veering or backing shift depending on what tack you are on. For instance, if you are sailing close hauled on starboard tack and the wind veers, that is lift. If it backs, that is a header. It is exactly the opposite on a port tack. If the wind veers while on a port tack that is a header and a backing shift would be a lift.
Part of the confusion in accurately describing and using wind shifts is that people often think the boat’s heading has something to do with it. In reality, your actual compass course does not matter. Headers and lifts, veering and backing are only based on clockwise or counterclockwise shifts and what tack you are on.
So how do headers and lifts apply to a cruising sailor? If you are beating towards your destination one tack will typically receive more headers and the other more lifts as the wind oscillates, though this is not always the case. By paying close attention to your sails and heading you can easily figure out if you are being lifted towards your destination or pushed away from it.
This is where your boat’s actual compass heading becomes useful. Start off sailing on one tack and take note of your heading. If you are trimmed properly, using your tell tales and steering well, you should be able to detect 10 degree or more shifts in the wind based on that heading. Then tack over and do the same thing on the other side. Chances are you will receive more lifts on one tack than the other. Or you could be a power boater and simply turn on the engine, but I’ll leave that decision to you.
VELOCITY SHIFTS
The other types of wind shifts that we experience while sailing are known as velocity shifts. This seems fairly obvious because we all know the wind changes in strength on a regular basis. But again, we have to give these shifts names too.
For newer sailors one of the hardest things to do is to learn how to see the wind on the water. The wind creates ripples that eventually turn into waves when given enough distance to travel. By looking at these ripples we can not only see where the wind is coming from, but also see if it is changing in velocity.
A velocity decrease in the wind is referred to as a lull and an increase is either called a puff or a gust. A lull is often recognized by flatter water or even a slick spot that can range in size from small to large. Lulls in the wind are notable because they may tell us that an even greater directional shift is bound to happen. But lulls also affect us like headers do. When sailing into a lull we experience a velocity header and aren’t able to sail as close to the wind so will have to fall off in order to maintain speed. Easing the sails out slightly to create twist will also help preserve momentum when falling off in a lull.
Puffs and gusts are velocity increases in the wind that vary based on strength. We have all sailed on a gusty day and heard weather reports calling for gusts of up to a certain amount of wind. Puffs are incrementally smaller increases in the wind and happen on very light wind days. A puff is distinguishable by small ripples or “cats paws” moving across the water and a gust will be a much darker patch of ripples that may even start to cap over.
If a lull in the wind was a velocity header, then a gust in the wind is a velocity lift. When your boat is hit by a gust, gets overpowered and rounds up into the wind—that is a lift. Often times if we see a gust coming we can steer up into it in anticipation of the lift. Doing that will help the boat heel less and may even provide an increase in boat speed. The tendency in a gust is to do the opposite, to ease the sails out and turn away from it. But if you use that gust to your advantage and feather up into it you will receive a nice lift while keeping the boat sailing relatively flat and fast.
Sailing wind shifts is not for every cruising sailor, but that does not mean that proper terminology and an understanding of how to take advantage of the shifts does not apply. Next time you are out for a day sail or on a passage, look at the wind on the water and how it affects your course and boat speed. Even picking up the slightest subtleties in a shifting wind can help you sail better and faster in light or heavy air and who knows, you might just beat everyone to your favorite anchorage without using the engine.