Riding the waves: how to sail and manoeuvre

Sailing in high waves can feel a lot like riding a roller coaster. If you don't manoeuvre correctly, you might experience jolts and juddering, endure long, tiring legs of the journey, or risk capsizing or colliding with an obstacle or the shore. However, it can also be a truly exhilarating experience, literally surfing the waves to your destination. In order to make sailing the high seas comfortable and safe, it is essential to understand how different types of waves are formed, how they behave and everything that influences them. 

Every sailor should understand the behaviour of waves and be able to set up and trim the boat to make the most of them while minimising their negative effect on the ride. This is a fundamental skill that everyone who wants to ride a boat should practice and develop. It is the only way to get the most enjoyment out of sailing and to have the self-confidence to be able to sail in all conditions.

A sea wave is the movement of a mass of water set in motion by wind (aeolian waves) or ocean currents. Of course, waves can be caused by earthquakes, the eruption of an undersea volcano, a landslide, or a glacier, but these are extreme cases, so we will focus on the typical waves encountered at sea. Waves are the rising and falling movements of water, characterised by a peak (crest), the lowest point (trough) and height (the distance between the crest and the trough).

Within the wave motion, the wave period is the time interval between the arrival of consecutive crests at a stationary point. The height and speed of waves depend not only on the direction and strength of the wind, but also on the water's surface area and depth. Different waves can add to or cancel each other out and have high inertia, so that they remain on the surface long after their source has disappeared. At the coast, waves tend to break and change shape. 

Sailing in waves also depends on how big a boat you are sailing on. Logically, the bigger the boat, the less trouble the waves will cause you. Objects bounce on the waves and are carried by them because they take energy from the waves. In sailing, this means that while the size of the waves is important, it also depends on the speed at which you are sailing. Because speed reduces the amount of energy that is transferred from the waves to the boat, setting it in motion and rocking it. At first glance, you may think that increasing speed in big waves is not the way to go, and in extreme conditions, a slower pace feels safer. However, it is by increasing speed that you reduce the risk of capsizing and making the boat less manoeuverable. With today's yachts, which you can typically sail in the Mediterranean and Adriatic, it is easiest to achieve consistently higher speeds when sailing downwind.

Modern boats can reach quite respectable speeds in waves when on a downwind course. However, the faster you go downwind, the more experience you need to have to manoeuvre your boat safely and reach your destination. 

Several factors come into play when steering a yacht in downwind waves. When you are surfing a wave at high speed, the rudder becomes much more sensitive than usual, and you only have to make subtle adjustments when steering. Otherwise, you risk sudden and abrupt changes in course, in the direction of the real and apparent wind and incoming waves, which can rock or even capsize the boat. The second factor is to choose the angle at which you ride the wave so that you are heading in the right direction into its trough. A good example is surfers who never ride a wave straight, but always at a perpendicular angle to its direction.

In practice, this means that as the stern of the boat starts to rise and the nose drops down, you should ease out of the waves slightly (that is, angle the rudder to leeward, turn the boat more upwind and possibly trim the sails) to give the boat more speed. The bigger and faster the wave is, the more you need to change course so that the boat's speed is as close to the speed of the wave as possible. The moment you start to surf the wave, do not head straight down into the wave. If you do, you will very likely dig the boat's tip into the previous wave, slow down sharply, the wave will roll past you, and the direction of the apparent wind will change substantially.

In addition, when a wave hits a boat, it transfers its energy to the boat, and if the boat is comparatively small in relation to the wave and moving slowly, it cause it to capsize. The ideal is to angle the boat so that it glides along the side of the wave (regardless of whether you are riding it "uphill" or riding it "downhill" so to speak). In addition to extending the surf time on the wave, this will keep the boat at a constant speed.

Riding upwind and against waves is much more difficult and uncomfortable than riding downwind in waves. Even a slightly undulating surface can significantly reduce your speed and ability to stay on course. This can sailing quite a bit longer and you will also be less comfortable. However, if you have no choice but to sail upwind in waves, you'll want to know how to guide the boat so that you don't have to use the engine as additional propulsion. As in any situation, strategy and tactics depend on specific conditions, but the basic lessons remain the same.

A wave is created by the movement of a mass of water in a cycle — upwind at the top and downwind at the bottom. As always, you must ride the waves so that you can use their energy to your advantage and increase the speed of the boat. The general rule of thumb is that when riding a wave "uphill", you should tack the boat slightly, and on the crest of the wave when going "downhill", you should be able to ride the wave (that is, the helm should be deflected to windward, the boat will start to turn downwind and the helmsman or trimmer should ease the sails so as not to risk capsizing the boat). This manoeuvre is done to spend as little time as possible with the boat on top of the wave while keeping a more or less straight course despite manoeuvring into the waves.

The best way is to set the sails to have the best possible performance over the widest possible range of different courses. This will deal with changes in boat speed and associated changes in apparent wind. If the waves are really high, the reference point for setting the sails should be based on the maximum speed you can reach at the top of the wave. In waves, you should also reef the sails much earlier than in normal conditions. Another good trick and alternative to reefing when sailing in stronger winds and bigger waves is to furl the sails, that is, to set them so that the top half near the backstay releases some of its power. It is common on racing boats in regattas to have the trimmer working with the sails constantly as the waves come up.

If you and your boat are struggling to ride the waves, it's time to start thinking about using your engine to help you. Especially in lighter winds. While using the power of the engine makes sense when sailing upwind in waves and gets you to your destination faster, using the engine doesn't make much sense when sailing downwind in waves. Downwind, the boat usually has enough speed and the only result will be that you will use more fuel without achieving the desired performance.

For experienced skippers, helmsmen and crew who have logged many hours at sea, riding the waves is a fun and adrenaline-filled experience. However, if you have more beginners on board or crew members who are prone to getting seasick, or if the situation is generally beyond you, there is no point in worrying and continuing your journey. In these cases, always keep a list of marinas on your route handy to fall back on in challenging conditions.

Autopilot and waves don't usually get along. Of course, technology is always evolving, and new systems of auto-navigation and auto-steering of the boat are becoming more and more sophisticated, allowing them to adjust the heel, change course and even work with apparent wind. Yet no instrument can replace the experienced eye and hand of the captain or helmsman. Technology and instruments should serve as an aid rather than an all-powerful tool. Even on a boat without the latest technology, it is often easy to rely on the system's calculations instead of just following the compass. So, if you want to use the autopilot in waves, you should be sure it is flawlessly and correctly set up.

Sailing in the waves has its own set of challenges that need a certain amount of skill and feel for steering the boat, as well as knowledge of navigation and navigational aids. However, if you grasp the fundamentals and understand the different sorts of waves and how they behave, riding the waves can be an unforgettable experience. As is always the case at sea, you need to be well prepared, assess your experience and strengths correctly, and don't put yourself at any unnecessary risk.