 Many native Australians would agree that this strip of sunny coastline along the country's eastern seaboard is a surfer's paradise. But to a team of researchers from the University of Wollongong, it's also their laboratory. Combining their expertise in materials engineering and 3D printing, they're learning how to produce and test tailor-made surfboard fins more quickly and cheaply than ever. While the surfboard dates back hundreds of years, playing a central role in ancient Polynesian culture, the surfboard fin is a relatively new invention, first added in the 1930s. Much like it does for the many marine creatures who sport one, the fin gives surfers the stability and control they need to maneuver across the water. But surfing needs can vary widely between different riders. Some of the Australian team's research shows that pro surfers can generate more than three times as much power as intermediate-level surfers as they whip their boards up and down waves. And while surfboard fins have evolved to suit different riding styles, the options offered by fin makers are limited to mass-produced designs. That's where 3D printing comes in. Within a matter of hours, the research team can dream up and build an entirely new fin design. Using materials that match the properties of mass-produced fins, the team can make functional parts on demand. What's more is that they're uniquely situated to test that design almost as soon as it's printed, as they're only minutes from the nearest surf spot. Results gathered from this incredibly short production cycle, recently published in the journal MRS Advances, show that the 3D printed fins measure up well against commercial fins found in most surf shops. When tested in the lab, the team's homemade designs made from carbon fiber and polymer-based composites showed similar mechanical properties. And when fitted to surfboards decked out with sensors recording riders linear and rotational speed, position, angle, and power, the fins led to similar performance. More combinations of materials and fin shapes still need to be tested, but the team's approach could lead to unparalleled levels of customizability, which is crucial in a sport where more and more athletes are looking beyond the shelves to find the ultimate riding experience.