Surf Simply MagazineFinding Your Feet 

A Proposed Shoe Design To Improve Surfing Performance

Getting better is always the goal, and in surfing, this basically means catching more waves and standing on the surfboard longer, performing the movements you want. It’s a never-ending quest to find one’s feet — both literally and figuratively.

“Regular booties are quite thick, so we mostly wear them in colder weather to maintain our body temperature, whereas surfing barefoot provides a better feel for the feet, but it also exposes us to issues like getting scratched by rocks,” says Haocheng Lou, a surfer and footwear designer whose Master’s thesis explored ways to achieve a middle ground between performance and protection. “Conversations with fellow surfers further emphasised the crucial role of our feet in maintaining balance and control. So, I saw an opportunity to address this challenge by designing a specialised surf shoe.”

The design borrows largely from nature. It mimics the manta ray's wings in the laces for added foot protection, and the gills for the water drainage system. Meanwhile, the shoe's friction function takes cues from the gecko and tree frog, animals with remarkable grip and flexibility. The gecko-inspired sole texture design featured a layered structure resembling scales, to maximise contact area with the surfboard and ensure optimal traction; the sole texture based on the tree frog's toe pad structure consisted of hexagonal cells and grooves that allow fluid to pass through. “Biomimicry is currently a trend in design,” says Lou. “There is a rationale behind drawing inspiration from animals – everything in existence has a purpose. Take a tree frog, for example. The structure of their feet evolved into a shape that best suits its needs over time.” Finally, to provide surfers with better foot control, a split-toe design, inspired by Tabi socks (a traditional Japanese sock), separates the big toe from the rest and the heel, offering three distinct stress points for improved safety, comfort, and stability.

To enhance surfers' perception of their interaction with the surfboard, Lou’s surf shoe design incorporates raised interaction modules on the outsole. These modules respond to changes in foot pressure as surfers execute various manoeuvres, providing consistent force to improve awareness of their feet and the board. Testing involved a surfer standing on heat-sensing pads and mimicking surfing movements on a simulated surfboard to obtain accurate foot force maps. These tests revealed three primary pressure areas on the foot: the toes for grip and sensitivity to placement changes, the ball for stability, and the heel for overall body support. This data informed the development of four distinct interaction module concepts tailored to surfers' needs, which were then transformed into physical prototypes and assessed by 23 participants, who provided feedback after wearing them and executing typical surfing manoeuvres.

The final design comprises four parts, all put together using Gorilla fabric glue and stitching: Velcro straps resembling manta ray wings, which offer protection and ease of use; manta ray gill-inspired side drainage holes; an insole featuring raised modules for improved surfboard control, made from 1/4-inch EVA material for durability and lightweight comfort; and a 3D printed outsole and comfort layer combination with a biomimicry texture to ensure optimal friction for various surfing actions. The outsole also employs a raised interaction module design to heighten awareness of the shoe's interaction with the surfboard, using a flexible resin material developed independently for eco-friendliness, lightness, and 3D printing customizability. The upper comfortable layer was crafted from highly permeable nylon sport mesh, while Velcro straps offer high cycle life, durability, reusability, and performance.

The final product was evaluated through A/B testing, comparing surfing performance under three conditions: barefoot, wearing the designed surfing shoes, and wearing existing surf shoes. Surfer Ruru Liu was the representative in the test; he surfed at least five times under each condition. Data on surfing pathways, wave count, ride length, and surfing time were collected, analysed, and organised into a table featuring the mean surfing time for three selected rides, as well as the average time for each condition. The results showed that wearing the designed shoes allowed for nearly equivalent surfing time as being barefoot, and it was 14.2% longer than when using existing surf boots. As Lou intended, the primary function of enhancing surfboard control was confirmed through the data. The secondary function of providing foot protection, on the other hand, was validated by testers' feedback on the shoe's comfort and sturdiness.

Still, the research was not without limitations. One issue was that the sample size of interviews was relatively small for a design that targets such a wide audience, and this affects the validity of the feedback. Another challenge concerns 3D printing’s material and time-consuming nature, which make it suboptimal for mass production.

As for the product itself, Lou identified two main areas of improvement. Firstly, exploring alternative stitching methods for bonding the upper and outsole in order to reduce adhesive use and achieve sustainability goals. Secondly, addressing stitching issues caused by the thickness of 3D printed material to upgrade both aesthetics and durability.

When asked how he sees the surf shoe’s function evolving in the future, Lou highlights the role of sustainability, particularly in focusing on ESG principles, as well as increased customisation through 3D printing, which would allow tailoring shoes to the user's foot shape to provide a better experience. That said, he’s also cognisant of the fact that, in the current surfer collective consciousness, the notion of applying one more layer of wax remains more appealing than surfing with shoes on. "Many people still prefer going barefoot,” he says. “However, with outdoor activities gaining popularity, more individuals are exploring surfing, and becoming more proactive in selecting their surfing gear.”

Proactive or reactive, there’ll come a time when better is not better, and rethinking the way we see and use our feet — indeed, experimenting with our feet — is certainly a way of keeping up with performance demands.

Or perhaps all we need is someone to win the CT with shoes on?

Reference: A Proposed Shoe Design to Improve Surfing Performance [979-83-7984-942-9] Lou, Haocheng, 2023.