Surfboard volume is really just a measurement of how big the surfboard is. Throughout most of surfing history, if you turned a surfboard over, somewhere on it would usually be written a set of dimensions like “6’6” × 20” × 2.5”” or “5’7” × 19” × 2.25””. What those numbers mean is that the board is six foot six inches long, twenty inches wide, and two and a half inches thick at its thickest and widest point.

The unfortunate thing is that those measurements actually tell you very little about the surfboard itself. You could take those same dimensions and design three completely different surfboards that would all behave differently in the water. Two boards might share the exact same length, width, and thickness, but have different outlines, rails, rocker, concaves, and overall design concepts.

For most of surfing history this was not such a big problem, because whatever the best surfers in the world were riding, most other surfers were basically riding the same thing as well. If we go back to the 1940s, there was some variation between boards, but they were all generally built around the same ideas. Into the 1960s everybody was riding longboards.

Some may have been 9’0”, some 9’6”, some 10 foot long, but they were all relatively similar in design. Into the 1970s the boards got shorter, the shorts got shorter, and high-performance surfing began progressing further and further.

This trend continued all the way into the late 1990s and early 2000s, where surfboards reached a point where the boards elite professionals were riding barely even worked for normal surfers anymore. In many cases they did not even work particularly well for the professionals themselves unless they were surfing in very powerful waves and standing in exactly the right spot on the board. These boards became extremely hydrodynamic and sensitive, but also unstable and unforgiving. If you were not surfing powerful waves with excellent technique, the board would often just bog down and feel difficult to ride.

At the same time, surfing entered what became known as the “retro revolution.” People started going home, pulling old longboards and fishes out of garages and rafters, and discovering that these larger, higher-volume boards were actually far more enjoyable to surf in everyday conditions. They paddled more easily, caught waves earlier, and generally made surfing more fun.

The result is that nowadays you can go down to the beach and see every possible shape and size of surfboard being ridden at the same time. Because of this huge variety in design, surfers needed another way to estimate whether a surfboard would actually work for them.

This is where volume became important. Surfing borrowed the concept from the windsurfing community, where boards had already been measured in liters for years. It is slightly strange because surfing still uses imperial measurements for length, width, and thickness, but switches over to metric for volume. Windsurfing, being more European-influenced, already used liters as the standard measurement, so surfing adopted it as well.

Volume is essentially a measurement of the total space inside the surfboard. If a surfboard were simply a rectangular block, you could calculate the volume by multiplying length × width × thickness.

But surfboards are not blocks. There is not a single straight edge on most surfboards. They are made up of curves, rocker, rails, concaves, and complex shapes.

Historically, this made volume extremely difficult to measure accurately. One of the only ways to do it was to literally fill a bathtub with water, submerge the board, and measure how much water overflowed.

Nowadays, most surfboards are designed digitally on computers, even many hand-shaped custom boards. Because the board exists as a digital model first, the computer can calculate the volume very easily.

As some general ballpark figures, modern high-performance shortboards might sit somewhere around 25–35 liters of volume, while a traditional nine-foot longboard may be somewhere around 70–80 liters.

So what does volume actually do for us, and why do we care about it?

The reality is that the human body is not very hydrodynamic in the water. Without a surfboard there is a huge amount of drag and resistance. Even a small surfboard lifts part of your body out of the water and provides a smoother, harder, cleaner surface to move through the water with. This immediately helps you paddle faster and more efficiently.

As the volume increases, more of your body is lifted clear of the water. On a large longboard, almost your entire body can be supported above the waterline. The board creates a slick, efficient planing surface that allows you to paddle significantly faster and with much less effort.

That extra paddling speed is extremely important because the faster you are moving, the less steep the wave needs to become in order for you to catch it. A surfer on a longboard can begin paddling into a wave and get to their feet much earlier than someone on a shortboard. Meanwhile, the shortboard surfer has to wait for the wave to become steeper and more powerful before they can generate enough speed to catch it. A body surfer, with no board at all, has to wait until the wave is practically breaking on top of them before gravity can accelerate them enough to ride the wave.

By increasing the volume of the board, we make the board float better, paddle faster, and catch waves earlier and more easily. In many ways this simply makes surfing easier and more accessible.

However, surfboard design is always a balancing act. Almost everything in surfboard design exists on a sliding scale between maneuverability and responsiveness on one end, and speed and stability on the other.

Increasing volume generally improves paddling speed, stability, and wave-catching ability, but it also reduces responsiveness and maneuverability. Lower-volume boards are more sensitive and easier to turn aggressively, but they require better technique, steeper waves, and more precise surfing.

In the end, volume is simply a tool for matching a surfboard to the surfer and the conditions. More volume improves paddling, stability, and wave-catching, while less volume increases responsiveness but demands more from the surfer.

For a long time, surfing culture treated smaller boards as more advanced, but the best board is really the one that helps you catch waves consistently, move comfortably, and enjoy your surfing. Often, a little extra volume can make all the difference.