August picked up surfing in the 1950s, when the sport's popularity had just begun to grow. His father, Blackie August, was also a noted surfer. His enthusiasm and his involvement in The Endless Summer influenced the growth of the sport over the following decades. His surfboards are sold under the Robert August Surfboards brand and are produced by Surftech, a company that manufactures lightweight epoxy surfboards. He continues to travel the world promoting surfing, and in 1994, he was involved in the filming of The Endless Summer II, in which surfers Pat O'Connell and Robert "Wingnut" Weaver retrace the places visited by August and Hynson thirty years earlier. He took part in the film Step into Liquid.