It is believed that surfing was first started around 400 A.D. by the ancient Polynesian people living in Hawaii and Tahiti. These days, we can see people enjoying surfing on just about any coast in the world, regardless of the season. It continues to grow as a competitive sport, with competitions of all sizes, from small-scale competitions to world-class championships. Surfing is a simple but intense sport. The surfboard is used as the sole equipment to ride naturally generated energy (waves). For this interview, we visited a surfboard shaper. It is the surfboard shaper that holds the key to a surfboard’s performance, which governs the appeal of surfing.
Masao Ogawa - Surfboard Shaper
Ogawa performed as a top pro in the early days of pro surfing in Japan. He is a veteran as a shaper with over 30 years of experience. He currently holds an important position in the Association of Surfing Professionals (ASP) JAPAN and he's also a competition judge. The boards that he shapes for the world surf brand “Dick Brewer Surfboards” and his personal brand “OGM Surfboards” receive wide acclaim, from leisure surfers to world tour competitors.
A shaper governs the performance of a surfboard
— First, tell me about the role of a surfboard shaper.
A shaper is responsible for the first stage in the surfboard production process. They shape the materials into the form of the surfboard, which is the most important part. A surfboard can be made from two types of materials, urethane foam and polystyrene foam. Each material has a different weight and strength. It's the shaper's job to choose the material and shape it into the surfboard's shape. This process determines more than 90% of the board's performance.
A shaped board is then colored and painted, and coated in glass cloth and polyester resin.
― What parts of the shape are important in determining the performance of the surfboard?
All parts of the surfboard affect each other. We can't simply say that some parts are more important. There are three points which have a major impact on the performance of the surfboard in particular: 1) the overall shape of the board "outline" such as the board's length, width, thickness, and capacity (volume), 2) the curve "rocker" that is given to the board's front tip (nose) and back (tail), and 3) the shape of the side "rail" (see figure 1).
Figure 1: Names of the parts of a surfboard.
A surfboard rides along the boundary between water and air
― What process is used to shape a surfboard?
The first thing is to decide on the outline. A sharp angle in the overall curve makes it easier to turn. A surfboard rides on a wall of water. The board itself has no propelling force, but the board drops down along the slope of a wave. This gravity becomes the propelling force. If the waterline length (the part that is in the water) is short when riding along a wall of water, there will be no resistance and the board will glide along more easily. This means that there is greater movement if the outline has curves rather than a straight line.
Next is the rocker (curve). A stronger rocker reduces the surface that is in contact with the water, making it easier to maneuver. However, a board like this will sit deeper in the water, slowing it down.
If the rail is thin it sinks more easily, so it is easy to lean the board, but if the board is submerged under too much water there is more resistance and it will not move as fast. I shape the rail based on the surfer's leg strength. For example, a slender person with a body weight of 70 kg and a height of 180 cm requires the same capacity as a person that is the same weight but who has more of a rugby player physique at 170 cm in height. However, the optimal rail shape will be different for these two surfers. The former body type is likely to have less leg strength so it is better to have a thinner rail—in other words, a board that requires less strength to turn. On the other hand, the latter body type has more leg strength so a thicker rail will not affect their ability to turn. On the contrary, if this surfer rides a board with a thin rail, it will be constantly fighting more resistance from the water and will not be able to pick up speed, so a thicker rail is more suitable for this person.
When riding a wave, you want to always be repeating turns more or less from side to side, rather than sliding straight from the top of the wave to the bottom of the wave. This means that you always want one of the rails in the water rather than having the entire bottom of the board sitting level on the water. For this reason, there is a particularly strong relationship between the outline, rocker, and rail when determining the maneuverability of the surfboard, and all of these parts need to be considered jointly.
If you add rocker to a two-dimensional outline to give it some curve, it becomes three-dimensional, so we often detect distortions and disturbances in the outline when we add the rocker. I check the relationship between all of these parts and the balance between each part to determine the adjustments that need to be made.
― Okay, so it's important to have a design that allows for speed without resistance from the water. Do you have a formula for that?
A surfboard rides along the boundary between water and air. If the board was fully submerged in water, this could be resolved simply using fluid dynamics. However, we also have to consider wave resistance. There are a lot of parts that cannot be resolved using solely one theory or logic.
For example, if the waves are small and the surfboard is moving slowly, the buoyancy, which is determined by the surfboard's volume, is important. If there is not enough buoyancy, the surfboard sinks. On the other hand, if the waves are big and the dynamic lift increases as the surfboard picks up speed, the board is able to float even if there is not much buoyancy.
I'll use a motor boat as an example to describe the relationship between buoyancy and dynamic lift. As a motor boat picks up speed, the front rises into the air. This is because the dynamic lift increases proportional to the square of the speed. In other words, if the speed doubles, one-fourth of the area is required to generate the same dynamic lift. The same thing applies to a surfboard. When the surfboard is running and it picks up speed, the surface that is in contact with the water drops down at the back, and the area that is in contact with the water decreases. For this reason, boards with a wide tail end up floating with only the tail, and the front of the board rises into the air, so the surfer can no longer control it. This is not a good shape. I also need to consider the various elements for a design that can respond to changes in speed.
The characteristics of hand shaping and machine shaping
― I have heard that machine shaping is becoming common these days, rather than hand shaping. How do hand shaping and machine shaping differ?
The advantage of machine shaping is the reproducibility. For example, if you need to change just one part of a shaped board, this is very difficult to do by hand because, no matter what you do, other parts of the board end up changing as well. If you do it by machine, you can make a perfect change to one part. The machine is a far superior tool for improving a partially completed design.
However, you can't beat hand shaping when you're creating a new board design. There is a lot of freedom in machine shaping software and a very specific shape can be set with this software. However, even when looking at the design in 3D on a screen, it is still difficult to know exactly how the board is going to turn out. I need to be able to draw an outline in pencil and make subtle decisions like whether to cut on the inside of the line or the outside of the line. Machines have not reached that level yet. When shaping a board, I need to think holistically about the build, weight, and height of the surfer, where they will be surfing, and what type of waves the board needs to be able to handle. I don't get the sense that the numbers can be applied digitally. This aspect is at the core of the design and it really needs human experience.
A shaper is not a "craftsman"
― A shaper is focused on shaping technology, but it's important for designs to be born from experience of surfing and building surfboards, isn't it? Is that why so many of the top pros want your boards?
The shaping technology can be perfected given another ten years and, it may be excessive to say anybody, but it's a technology that almost anybody will be able to use with training. When shapers are referred to as "craftsmen" it is typically a reference to the shaping technology. However, what is important is the theory, such as the physics and fluid dynamics, and creating a design that also encompasses the various elements that are not covered by the theory. And then to brush up the design based on actual experience.
― Finally, what do you consider to be "the ultimate board"
As we have discussed, the performance and characteristics of a surfboard are determined by the subtle combination of the outline, rocker, volume, and the shape of the rail. However, the most important point when deciding whether the board has good form is whether the characteristics of the board are a good fit for the surfer. The ultimate surfboard will therefore vary depending on the person. For this reason, a shaper needs to understand the surfer's body type, surfing style, and the waves that the board will be used on, and then determine a design based on these factors plus theory and experience.
― I understand now that a surfboard shaper cannot rely solely on "sense." It requires a great deal of experrience and intimete knowledge.
― Thank you very much for your time.