Sailing off of the wind is easy to do and understand: you point away from the wind’s direction, it fills your sails, and you move forward.
Most sailors consider upwind sailing to be when you are sailing as close to the wind as possible.
It is impossible to sail directly into the wind, although the modern high-performance sailing boats can go faster than the wind, and they create an “apparent wind” and can reach less than 20 degrees off of the true wind.
Here’s What “Sailing Upwind” Actually Means:
“Sailing upwind” means you are sailing as close to the direction the wind is blowing from as possible. Upwind is about 45 degrees away from the true wind direction for most sloop-rigged boats. More modern racing sailboats can get closer to 30 degrees off the wind.
When Are you Sailing Upwind?
Sailing upwind happens when you start pointing the sailboat closer to the direction the wind is coming from.
Technically, any point higher than a beam reach (where the wind is blowing directly perpendicular to the boat) might be considered upwind sailing.
Most sailors consider upwind sailing to be when you are sailing as close to the wind as possible. This is called “close-hauled,” as all of your sails are hauled in as close to the rig as possible.
How close you can point to the direction of the wind varies by the kind of sailboat that you have. Just about every modern sloop-rigged sailboat can get about 45 degrees off of the wind.
Most sailboats that are racing designs can get much closer than that. Many can point as high as 30 degrees off of the wind.
Like America’s Cup foiling catamarans, more recent high-performance boats can get as close as 20 degrees, or even less. These boats go faster than the wind.
They bend it around their trajectory and create a new “apparent wind,” which feels as if it is directly blowing over the boat’s bow.
How Does Sailing Upwind Work?
Mechanically, you sail upwind by hauling in your sails and pointing the boat as close to the wind as you can while still maintaining your forward momentum.
If you point too high (too far into the wind), the sails will start to flutter and backwind. Your boat will slow and stop, or even tack inadvertently.
If you are just starting on your sailing experience, you will want to sneak up on this point of sail, particularly if you are teaching yourself. After you have done it a couple of times, you will develop a feel for how the boat responds to the new point of sail.
Sailing upwind can be tricky in lighter air as the wind direction can be shifty. Many experienced sailors experience accidental tacks while racing in light air, as they are pointing as close to the wind as they can, and it suddenly shifts on them.
When you are pointed close to the wind, and your sails are trimmed properly, you generate lift, and you can sail upwind.
How is Lift Generated by a Sail When Sailing Upwind?
The way a sail generates lift is not complicated.
Picture the wind blowing toward the boat’s bow at a 45-degree angle. As it blows against the sails, it splits to either side of them (assuming they are properly trimmed!). At this point, the sails act similar to an airplane wing.
The wind that is split joins again behind the sails. The wind that traveled on the leeward side of the sails has moved farther than that to windward. When it meets again, the sails have forced it to change direction to directly astern of the boat.
In this way, lift is generated: the wind is bent into a new direction by the sails.
What Prevents the Boat from Being Blown Sideways?
This is because of the keel. It provides a balance to the force of the wind, allowing the boat to be lifted by the force it is generating.
Many sailboat designers and sailmakers in the 1950s and 1960s originally believed the sail to be identical to a wing section, but this was erroneous. That is because of the wind gradient.
The wind gradient refers to the difference in wind speed at various heights off the water. As the wind blows over a surface, that surface causes drag.
So the further you are above the surface, the stronger the wind is. The wind is stronger at 15 feet above the water than at the surface and even at 30 feet. Sails are designed around this principle, being fuller toward the top and flatter toward the bottom.
Unlike an airplane wing where the wind is a consistent speed from the fuselage to the tip of the wing.
So while the cross-sectional physics are different between airplane wings and sails on a sloop, the lifting principle is the same.
Is sailing Upwind a Good or Bad Thing?
Sailing upwind is a necessary thing. Whether you are racing or cruising, at some point, you will need to reach a particular channel mark or a port.
Sailing upwind is generally not as pleasant as sailing off of the wind. The boat heels more, and on heavier air days, you might take a pounding as the boat beats into waves.
On the other hand, some boats are exciting to sail upwind, like some catamaran models or the newer foiling sailboats.
Sailing upwind is neither good nor bad. Some people might enjoy it, but many do not.
There is an adage in the sailing community that a true cruiser never sails upwind; instead, they will crank up the iron genoa (the engine). Most casual sailors would rather be sailing off the wind than into it.
Is it Hard to Sail Upwind?
In general, it is not hard to sail upwind. It might not be particularly comfortable, but it is not difficult in most cases. Even on lighter air days, you can watch the telltales on your sails, and they will tell you whether you need to point up or down and what the wind is doing.
However, it can be hard when very strong wind, particularly for extended periods. This is because waves will pound your boat as you sail into them. Even if your sails are comfortably reefed, you will probably get battered.
This usually applies to racers trying to reach a windward mark or are on a distance race and going for a particular point.
Ocean cruisers will often find themselves in harsh weather and trying to make headway into a storm. This can be very hard, physically and mentally.
In that situation, many cruisers will drop their sails and throw out a sea anchor to keep their bow pointed into the waves to avoid capsizing and go below to ride out the storm.
What Are the Best Tips for Sailing Upwind?
As with most things sailing-related, there are a hundred pieces of advice from just as many sailors on the best way to sail upwind.
Assuming you are in a sloop, the forward part of your genoa is the main thing to watch. The forward part is pushed the furthest into the wind, and as your genoa goes, so goes the rest of your boat.
Assuming you are trimmed properly, you will need to focus on the telltales.
If your windward telltale is squirrely, then it is not getting good flow, and you should point further off the wind until the air is flowing better across that face of the sail; at that point, the telltale will be streaming straight back again.
Similarly, if your leeward telltale is not streaming, then that side of the sail is not getting proper airflow. Gradually point up until it starts streaming back.
Most sailors, when sailing upwind, will just go by their tell tales, as they will indicate subtle changes in the breeze, like lifts or knocks. The best racers get dialed into these and can make up a lot of ground on their competition by responding smoothly to these changes.
Sailing upwind is usually not the favored point of sail for too many sailors. For every sailor, it is a necessity at some point.
As with everything sailing-related, the best way to prepare is simply going out and doing it. Sailing upwind is usually not difficult, excepting certain conditions like heavy air.
And if you are cruising, and sailing upwind does get difficult because of waves or boring because of light air, there is always the iron genoa.