Which Sail Size Do I Need For Windsurfing? (What You Should Know)

Large sail, small sail, or in between?

These are the choices faced by a windsurfer who anxiously looks forward to getting on the water and enjoying their favorite sport.

Choosing the right sail need not be rocket science, as there are some factors to consider before your sail is rigged on the mast for your session.

Considerations should be given to your size and the strength of the wind as well as your level of windsurfing.

From geeky calculators that you can find online to watching what your friends are rigging, there are a plethora of choices to make your windsurfing experience a happy and enjoyable one, rather than one filled with frustration.

Which Factors Influence My Choice of Sail Size?

Sail size, your size, your skill level and wind strength – they all matter when determining which sail to use. A combination of all of these factors will help determine the sail size to use.

Sail Size Range

Sail sizes typically range from 2.0 to 10.0 m² (there are smaller and bigger ones available, though).

If you own a few in different sizes, you will be choosing the one that is best for the conditions. High wind will call for a smaller sail, while light wind will demand that you rig larger.

If you only own one sail, learn more about downhauling and how it can affect the use of the sail.

Before you buy a sail, discuss your size and needs with the shop you are buying from, as a 5.5 m² might be a fine all-around sail for some but might not be right for you.

Why Your Size Matters

A bigger sailor might choose a 6.5 m² sail in light winds, while a small person might get the same kind of ride with a smaller sail.

A man who is 6′ tall will need more sail to get going, such as a 6.5 m², while a woman who is 5′ tall and 100 lbs needs a small sail, such as a 4.0 m² in the same wind and water conditions.

It will take more sail to power up a board of a heavy weight sailor as opposed to another sailor with a small light weight frame, when the winds are lighter.

In stronger wind, however, a heavier and/or stronger sailor is able to manage a bigger sail than a smaller person, using their strength and weight within the harness to balance against the force of the wind.

Why Wind Strength Matters

The largest factor when deciding which sail to use is the wind that day.

Is it windy? Is it light wind? Is the wind forecast to be stronger? Are you willing to re-rig or change sails if the wind dies or picks up?

All of these questions can influence which sail you decide to use for the day, if you have several sizes. Talking to others can also help you decide, as you see what sails others are rigging for the conditions.

Wind strength is the deciding factor in choosing the sail for your session. You do not want to be overpowered or underpowered by selecting a sail that is wrong for the conditions.

Knowing the wind and water conditions before you leave your house is very important to your fun as well as safety.

For example, let’s assume a “small craft advisory” has been issued by the National Weather Service. This means the wind will be 25 to 38 miles per hour (22 to 33 knots), and a red flag is flying.

You mostly sail on a usually calm nearby bay. In this case, you would consider using your smallest sail, if you go out at all.

This wind would be for the advanced windsurfer, who would most likely have a small sail in their quiver.

Why Your Skill Level Matters

All other factors being equal, a less experienced windsurfer will rig a smaller sail than a more advanced windsurfer.

This is because as your skill level increases, you learn to control your rig more effectively.

This, in turn, will allow you to use a bigger sails and go faster in stronger winds and generally more challenging conditions, where a beginner would be overpowered and unable to maintain control of their gear with that sail size.

On the other hand, you will also observe the following seeming (but not actual) contradiction: as you advance, you will be able to start planing sooner with a smaller sail than a less experienced windsurfer.

That’s because you’ve refined your technique and increased your ability to translate the power of the wind more efficiently into forward movement and speed.

Of course, that doesn’t necessarily mean that you will choose to rig a smaller sail, but it’s important to recognize that you will be able to use it more efficiently than you previously could.

In other words, as you progress and increase your skill level, you effectively increase your usable range of sail sizes for a given wind situation.

How To Determine Which Sail Size To Use

Once past the beginner stage, you might have several size sails in your quiver. They can range from small to large. The best way to determine the sail for your session is to:

  • Watch the forecast and current wind speed
  • Talk to others at the sailing spot
  • Determine the best sail for you
  • Learn about sail size according to experience

Then rig the right sail for that day and conditions.

If you only have one sail, you might adjust the downhaul.

Otherwise, after getting the forecast, pack more than one sail in your car. After reaching your sailing spot, observe what the other sailors are rigging.

Then adjust your choice of a sail to your own body size, using your favorite sail for the present conditions.

This short video gives you a good overview of high-wind and low-wind sail sizes:

Practical Tips: Rule of Thumb for Choosing the Right Sail Size

Now that you know the theory, it’s time to give you some practical, actionable tips.

The following sail size recommendations may serve you as a general rule of thumb during your early days of windsurfing, until you develop a more refined instinct for the right sail size based on your experience.

Since you already know that the “right sail size” depends on many different factors (as mentioned earlier in this article), let’s focus on the two most important factors: the wind speed and your body weight.

To use the following table, simply choose the row which is closest to your weight and then move along that row to the right until you hit the wind speed you’re interested in.

At the point of intersection of your body weight and the wind speed, you will find a recommended sail size:

body weight12 knots15 knots18 knots21 knots
120 lbs (~55 kg)4.6 m²3.7 m²3.2 m²
140 lbs (~65 kg)5.4 m²4.3 m²3.6 m²3.2 m²
165 lbs (~75 kg)6.3 m²5.0 m²4.2 m²3.6 m²
190 lbs (~85 kg)7.1 m²5.7 m²4.7 m²4.0 m²
210 lbs (~95 kg)7.9 m²6.3 m²5.3 m²4.5 m²
Windsurfing Sail Size Recommendations (copyright: watersportgeek.com – published under the Creative Commons Attribution-NoDerivs 3.0 Unported (CC BY-ND 3.0) )

There are 2 notes I feel are important to make regarding the table above.

First, these sail size recommendations are mainly aimed at intermediate windsurfers.

So once you are past the beginner stage and able to safely sail in 12- 20 knots, the table is for you.

It will hopefully serve you as a solid starting point, meaning the recommended sail size you rig should at least be in the ballpark and not too far off from your desired sweet spot.

While the recommended sail sizes in the table are certainly not “wrong” for beginners or advanced windsurfers, they may be less applicable for them, and here’s why:

For beginners, the wind ranges mentioned in the table may simply be out of their comfortable range, since beginners typically learn in 12 knots or less.

Advanced and expert windsurfers, on the other hand, will typically use bigger sails than mentioned in the table since they have the skills to control more power. Besides, advanced windsurfers usually won’t need a table with sail size recommendations anymore, anyway :).

Second, you will notice that the differences (the increments) between sail sizes become increasingly smaller in stronger winds.

Example: If you notice that you are underpowered in 12 knots, you can easily rig a sail that is 1.0 or even 1.5 m² bigger.

However, if you notice that you’re underpowered in 21 knots, then you will increase the sail size by a much smaller increment (for example from 3.2 to 3.6 m²).

Sail Size Terminology: What Are Square Meters?

Using the symbol m², square meters are the way in which the size of the sail is defined. It is used to measure the surface area of the sail. In other applications, it could apply to a parking space for a car, which might measure 12 square meters.

Windsurfing sail sizes are determined by the square meter area. 1 square meter equals about 10.76 square feet.

Sail sizes typically range from 2.0 to 10.0 m². Adults learn best with 4.0 – 5.5 m² sail sizes.

Someone the size of a large child, however, might want to begin with a smaller sail, since uphauling the sail out of the water – which is the first step in windsurfing – is much easier with smaller sails.

What are Entry and Beginner Sails?

You will be pulling the sail up out of the water when you begin. Your sail needs to suit you and not your uncle, brother, or neighbor’s kid.

You should begin with a lightweight rig, which makes learning so much easier. A newbie windsurfer will get discouraged if pulling the sail out of the water – his first taste of windsurfing – is a difficult chore.

A lightweight small sail that allows to be uphauled and positioned might give someone confidence to move on past the first day. There is no race to win when it comes to beginning sailing.

In a previous post, I mentioned my own experience with sail size for a beginner.

You can buy an entry-level rig that includes mast, boom, sail and mast base. Beginner rigs are usually very light-weight and easy to handle.

Entry-level sails can come in 3.0 to 5.5 m². Depending on your size, you might want to choose an easy uphaul rig, meaning with a sail size of 3.0 to 3.5 meters and a lightweight mast and boom.

Several things that you might want from your beginning sail will be:

  • Can it be lifted out of the water easily?
  • Is it easy to control while learning tacks and jibes?
  • Is it stable when not planing?
  • Can I gain some power if the wind picks up?

You do not want cambers in a beginning sail, as they add to the difficulty of pulling it up and moving it to the other side. Also, a cambered sail could easily lead to much more power than the beginner is ready for.

How Does Sail Size Relate to Planing?

Planing is the next step in advancing to intermediate windsurfing. It means that the board has reached sufficient speed to travel across a minimal area of water.

It gives the feeling of lightness and flying and usually leads to the joy felt in windsurfing.

Intermediate sails are designed with this in mind. Additions make it easier to plane and stay powered up. Once the board is on a plane, you’ll be able to use a harness and the footstraps effectively.

Once you are at the intermediate level and want to plane and get hooked into the harness, your choice of sail will be important.

In lighter winds, a larger sail will get you going more easily. If the sail is too small, you might never get powered up enough to plane, and your experience on the water might be disappointing.

Without power, trying to use the harness is frustrating. Not being hooked in is fine if you are just cruising around, but many intermediates want to go faster and experience the thrill of planing.

You may want to consider Cambers when buying an intermediate sail since they allow the sail to capture more wind and therefore have more power than their no-camber equivalents.

What Are Battens, Cambers or No-Cambers?

The battens are the ribs of the sail and are there to give it shape. Often, beginner sails do not use battens.

You will see battens as you advance; they offer more stability, power and control when the wind is stronger and pretty much every sail beyond beginner sails has battens.

No-camber, full batten sails are usually Freeride, Bump-n-jump, Wave, or Recreational sails. Learn more about the tech side of rotational sails and camber inducers.

Camber sails, on the other hand, feature so-called camber inducers which are used to help keep and emphasize the shape of the sail. They are used in Freeride, Slalom, Race and Performance sails.

A Freeride sail might have 2 to 3 camber inducers. Some recreational riders prefer this type of cambered sail over the no-camber Freeride sail.

A Slalom or Race sail can have 4 cambers, while a Formula sail may have 4 to 5 cams. It can be very large at 10.0 meters to 12.5 meters. This type of large sail is used for light to moderate winds. It facilitates upwind pointing as well as downwind runs.

The upside of camber sails is that they “capture” much more wind, meaning you can get planing faster and reach a higher top speed than you could with a no-cam sail in the same wind conditions.

On the other hand, the camber inducers make the rig heavier and thus harder to handle. Additionally, because the camber inducers keep the sail in a fairly fixed shape, the sail becomes more rigid, meaning less flexible when it comes to changing directions in maneuvers.

What If You Only Have One Sail?

Having just one sail certainly makes your choice easier, once you are past the beginning level and are hoping to plane and get into the harness. No big decisions here, but using certain techniques will be important.

As mentioned in a previous post relating to downhaul, this would be something on which the intermediate sailor with just one sail would focus.

Adjusting the sail through downhaul tension is a method used by intermediate sailors with one sail.

Keep in mind that even though you can extend the wind range you can sail in by changing the downhaul tension, this is only feasible within certain limits. To make this clearer, let’s consider an example:

Let’s assume you own one sail, and the optimal wind conditions to use it are 15 kts. You may be able to use it from 12 to maybe 20 kts by adjusting the downhaul tension. But anything outside this range will be off-limits with this sail.

On the other hand, having additional sails is usually the next step in advancing to meet a variety of conditions while planing.

Helpful Tools

These days, one can find an assortment of charts and graphs, in addition to the one first mentioned, and even apps for your phone to determine what sail size is appropriate.

So, if you have a quiver of sails, you just look at the chart or at your phone on the beach to find out what to rig.

However, many calculators do not consider the ability of the sailor as well as if the water is choppy or flat.

Also, some windsurfers may prefer to be slightly overpowered, while others prefer to sail slightly underpowered.

Apps can be helpful, though, and the tech-geek experienced windsurfer will feel right at home using them.

Conclusion

There are many sails on the market these days. Your choice of Freeride, Race or Wave sails can depend on where you sail as well as the conditions of the wind.

Determining which sail size to use, assuming you have several sails, will be something you learn from experience while windsurfing.

Pretty soon, you’ll be able to rig the right sail just by standing on the shore and observing the wind. Until then, ask other sailors or use an app or online tool.

As a beginner, you do not need to know all of the technical aspect of sails on your first day of windsurfing.

Find the perfect beginner rig for your size and learning conditions (with instructor) and get out on the water.

The more you sail, the more fun you will have, and choosing the right sail will become easier with every session on the water.

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