There are a couple aspects of wakesurf board design that have an oversized effect on how a board rides. You can probably think of most of these pretty easily. Things like length, width, thickness, rocker, and outline. There’s more, but in general there are a limited number of features that contribute the most to how a board rides. While most of us have this intuitive sense of which features are most impactful, intuiting why that’s the case is much harder. If a boards length is important, then why? What is the difference between a longer board and a shorter board? What is the reason for that difference? 

Revisiting the why

You could ask similar questions about any feature, and for the most part the industry doesn’t have a good comprehensive answer. In fact, that’s one of the main ideas behind Smith Board Co. Beyond having this comprehensive understanding of what different features do, there’s not really any place to go to get an idea of all the knowledge we do have. So to remedy that, while we test and simulate to develop a deeper understanding of each feature, we started a line of blogs to understand what we as an industry do know about the science and impact of some of these important features. The first, and probably most obvious one, we wrote about was board size (which is, across the industry, a measure of the length of a board). You can take a look at that article here Why does board size matter?. 

For this article, we’re diving into the next most obvious feature, wakesurf board width. 

What is the impact of wakesurf board width?

The width of a wakesurf board obviously changes at almost every point of the board, so when we talk about width we’re really talking about the max width. It’s almost always going to be in the middle portion of the board, but depending on the outline, it won’t always occur at exactly half the length of the board. Most of the influence that width is going to have on a boards performance and ride characteristics is due to its contribution to the boards surface area. Specifically the surface area in contact with the water (what we’ll call Contact Surface Area). The more subtle influences of width on performance and ride characteristics are going to be due to the width’s contribution to the outline of the board. Things like if the max width occurs on the tail side or nose side of the halfway point, or if the board maintains more width (low curvature) or less width (high curvature). These subtle influences will be tackled in a post on board outline, so for now we’re just going to focus on the high level influence of width to board performance. 

 Wakesurf board width and surface area

The width of a board has a significant contribution, along with length, outline, and a few other features, to the overall surface area of a board. Surface area, and specifically the surface area that is actually in contact with the water (what we'll call Contact Surface Area), has an outsized role in a lot of aspects of how the board rides. So any feature that contributes to it is going to be pretty important in a boards overall ride and performance. 

Why is the surface area important? Well the contact surface area is where all the physical interactions between board and water takes place. It’s where lift is generated, where drag occurs, and where buoyancy is determined. As a general rule of thumb, any feature that increases a boards contact surface area is going to increase all three of those physical properties: lift, drag and buoyancy. It’s a little more subtle than that when you start taking all the different features of a board into account, but for the most part, the more contact area you have, the more opportunities and places there are for all of those physical interactions to occur. 

When it comes to width, a wider board is going to have a bigger contact surface area than a narrower board. According to our rule of thumb, that means it will have more opportunities to experience lift and drag, and more places where it is displacing water and creating buoyancy. When we say that a wider board has more opportunities to experience drag, that means that there are more places (underneath the board) where the water is essentially “pulling” back against the board which decreases its speed. A wider board will also have more front facing parts of the board (along the side rail) where the water hits it and essentially “pushes” against it also decreasing speed. These two aspects of the impact of width on drag ensure that, all other features staying the same, a wider board is going to be slower than a narrower board. A wider board will also experience more lift for the same reason, that there are more places in contact with the water where lift can be generated. Lift contributes to drive and offsets some of the speed losses due to drag, but in general not enough to counteract all of the drag contributions. 

Wakesurf boards width and buoyancy

The main benefit of a wider board comes from thinking about how it influences buoyancy. As we said above, a wider board is going to experience more buoyancy because it has a greater contact surface area. By itself that will help with planing which decreases drag and contributes to generating drive, but the main benefit comes from its contribution to a boards stability. The stability of a board is a direct result of how much the buoyant force can keep the board flat and steady. Think about a lever. If you push a lever farther out, the effect of that force will be greater than if you push the lever closer in. For a wider wakesurf board, the buoyant force is acting farther out from the center of the board and thus has a greater stabilizing effect. If the board dips down to one side, a wider board will “push back” harder than a narrower board and will feel more stable as a result. Because this is happening on both the left and the right side of the board, the wobble side to side in a board is dampened because more energy is needed to ‘fight’ against the increased effect of the buoyant force farther out along that lever. On a narrower board, the effect of the buoyant force is closer in on the lever, and the stability of each ride is more dependent on the balance of the rider. 

Understanding a wakesurf boards width and it's impact on performance

Understanding the impact of wakesurf board width on performance and ride characteristics is crucial for both riders and designers. As we've explored, the width significantly influences the board's contact surface area, which in turn affects the physical interactions with the water, including lift, drag, and buoyancy. These factors collectively determine how fast, stable, and responsive the board will be on the water. A wider board, with its increased surface area, offers more lift and stability but comes at the cost of increased drag, making it generally slower than narrower boards.

The stability provided by a wider board is particularly beneficial for riders seeking a smoother, more controlled ride. The enhanced buoyancy and the leverage effect of a wider board help keep the board flat and steady, reducing the side-to-side wobble and making it easier for riders to maintain balance. This makes wider boards a preferred choice for beginners or those looking for a more relaxed feel. On the other hand, narrower boards, with less contact surface area, tend to be faster and more agile, appealing to advanced riders who prioritize speed and maneuverability. These boards require a higher level of skill and balance, as they offer less inherent stability compared to their wider counterparts.

At Smith Board Co., our mission is to delve deeper into these nuanced aspects of wakesurf board design, providing the industry with comprehensive insights and data-driven understanding. By continually testing, simulating, and sharing our findings, we aim to empower riders with the knowledge needed to choose the perfect board for their style and skill level. Stay tuned for more detailed explorations of other critical board features in our ongoing blog series.