We take for granted that the tri-fin is the most common surfboard in the lineup. It wasn’t always like this. Throughout the ‘70s it was singles and twins. Single-fins had great holding power, but lacked squirt and speed in small waves. Twin-fins dashed and zipped and zapped, but had the tendency to slide out when you didn’t want them to. Many surfers of the era rode twinnies in small surf, and stepped up to singles when it was bigger. But the transition from one design to the other was a hurdle.

Enter Australian Simon Anderson, a surfer/shaper on the IPS World Tour, where contests were often held in small, weak waves. In October 1980, he noticed that fellow Aussie surfer/shaper Frank Williams had placed a small half-moon fin near the tail of his twin-fin as a stabilizer. Simon was inspired. He made himself a square-tailed board with three like-sized fins, all smaller than those used on a twin-fin. He called his new design the Thruster.

“It was obvious from the beginning that it was a huge leap forward,” remembers Simon. “But I had a little bit of trouble convincing other people. So I figured that maybe it wasn’t going to be that big.”

Simon showed up to the 1981 Bells Easter Classic with his new Thruster. In 12-15 foot waves, he won. Then, a couple weeks later, he won the Surfabout. Then, later that season, he won the Pipeline Masters. It was clear that Simon’s new design was the biggest breakthrough of the year. Twin-fin and single-fin surfers converted to Thrusters. Simon was named “Surfer of the Year” by Surfing magazine in 1981, and inducted into the Australian Hall of Fame in 1989. Surfer magazine listed him as the eighth most influential surfer of the 20^th century. And today, two and a half decades later, the tri-fin is everywhere.