What is tacking in sailing?

Tacking is one of those skills that can seem confusing to the new sailor, but with good instruction will quickly become second nature. The truth is: anyone can learn to sail. Rubicon 3 is committed to helping as many people learn to sail as possible; Some will want to stay local and sail on the occasional weekend. Others may dream of joining one of our expeditions to the Arctic or sailing across the Atlantic. Our ‘Learn to sail’ series helps you learn everything you need to know, from the very first steps through to advanced concepts. Today we look at tacking. What does it mean, when do we do it and how do we do it.

What does it mean ‘to tack’

There are many reasons why the internal combustion engine replaced sail for commercial shipping. Chief amongst them, though, would have been tacking. A sailboat can only head to within around 30-35° of the source of the wind. That is to say, if the wind is coming from 270°, a sailboat will not be able to sail a course of 270°. Instead, the closest it can get to 270° is 300° or 240°. Any closer to 270° than this, the sail will flap uselessly in the wind. If you want to understand why, imagine putting your hand out of the window while in a car. If you keep your hand flat and point it into the wind, it will wobble all over the place. But curve your hand slightly (sails are cut to have some curve) and point it just off the wind, and you’ll feel a real force on it.

So, if we wish to sail due west (270°), we will have to zig-zag our way west. We may start by heading at 300°, but after a while, to stay relatively close to our desired line of travel, we will want to change our heading to 240°. We will remain in this course for a while and then go back to 300° – and so the cycle continues. It is a slow way to head west, and a yacht sailing at 7 knots at 300° will only be making a Vector Made Good (VMG) of 6 knots, a reduction of 15%. 30° off the wind at 7 knots would be exceptional performance, however, and an average cruising yacht would probably only achieve 40° and 6 knots. This equates to a VMG of 4.5 knots, and only 64% of what a motor boat steaming at 7kn due west would achieve.

Now, every time the sailboat turns from 300° to 240°, it moves its bow through the wind. At 300°, it is on port tack (the wind hits its port side first). Once it has turned its bow through the wind and settled on 240°, it is now on starboard tack. This process of moving from one direction to the other is called tacking.

How to tack a sailboat

Now that we know what tacking is and why we need to do it, we need to know how to do it and how to do it well. We’ve seen how upwind sailing can have a significantly reduced VMG. To minimise this detrimental effect, we have to be efficient and precise in what we do. We want to minimise the time we spend with the wind not powering the boat forward, keep as much boat speed through the manoeuvre as possible, and minimise the sail’s flogging.

What angle will my tack be?

In our example above, we have been tacking between 300° and 240°, which gives us a tacking angle of 60°. Again, this would be an exceptional yacht. Most cruising boats, going from 45° off the wind from one tack to the other, will turn through 90°-100°. Assuming a right angle for your turning angle is not a bad rule of thumb.

When to tack

A beginner should not worry about this too much. Stay away from rocks and the shore (!) and don’t deviate too much from your intended route. As your understanding of the environment develops, you can factor in more inputs to your decision. Mostly, never feel overwhelmed by it. Some tacks will work well; others won’t. Enjoy it. Remember, we’re only doing this to have fun!

We saw that we would likely tack through 90-100°. Therefore, if you want to get past a mark, rock or headland, you need to hold your course until it is abaft your beam. That is to say, if you turn 90° toward it, you need to be able to get past it, not smack straight into it. At the most basic level, this determines when you need to tack. Now, you also need to factor in any current, leeway, traffic, and other factors – but this is a good starting point.

Other things to watch out for are wind lines. If you are in a nice breeze but can see flat water ahead, you will want to tack before you reach it, or you risk being becalmed. If there’s an option, it’s also better to tack in the smoothest water possible. Wait for a nasty wave pattern to pass and always have a good look around – and behind you – before you tack. It’s too easy to have missed another vessel nearby and tack right into their path.

The helm’s job

As the one on the wheel or tiller, you control when the tack happens. You need to give your crew time to prepare their positions, sheets and winches, so always give a preparatory “Ready to tack”. You must wait until your team says or shows you they are ready. Don’t start the manoeuvre until they are, or you risk damage or injury. Once everyone’s prepared, call “tacking now”. Start with a slow, smooth turn. This allows the boat to keep its momentum as it comes into the wind. As speed drops off, increase the turn speed and finish the tack. If it’s a choppy sea state, you’ll want to turn quickly from the start as the boat’s momentum will be lost quicker anyway. Ideally, you get the boat’s bow round in time such that the next wave helps you complete the tack, rather than knocks you back.

As you complete the tack, don’t try and finish hard on the wind. You need to rebuild speed first, as it’s only when it is you’re moving fast enough that you can point high. So finish turning a few degrees low, and then as speed rebuilds, you can edge back toward the wind.

The crew’s job

Once the helm has asked you to prepare for the tack, load the lazy headsail sheet onto the winch, making sure you have two or three turns around the drum. Too few, and you will not have control of the line; too much and you risk riding turns as you pull in the slack. As the boat’s bow goes through the wind, the ideal is to let the headsail back halfway, then briskly ease out a couple of feet of the sheet and finally ‘John Wayne’ it off – which entails spinning all the line off the winch with a rising, anti-clockwise movement.

At the same time, the new headsail sheet should be pulled in hard and fast. If it’s a big sail or you’re in a race, then while the slack on the new headsail is being pulled in, you can already be grinding the winch. This will dramatically speed up bringing in and trimming the new sail. It also reduces the chance of riding turns.

Tidying up

Once the yacht is settled on the new course, it’s important to tidy up the lines, ensuring trip hazards are kept to a minimum and sheets loaded on winches have safety turns. With all the work done, it’s time to put on the kettle and have a cup of tea…. until the next tack!