Photo: Robert Rosenberg/EyeEm

Illustration: Phil Roberts

Possibly the best way to harness wind over water. Photo: Jeremiah Klein

*Note that a swell with a period of 10 seconds would decay down to basically nothing before reaching Southern California, but this still gives us a cool grasp of the speed of various swell periods.

Cyclone Pam was one of the longest-running storms ever recorded, spawning swell from the Central Pacific to Australia, New Zealand, South America, Central America, Mexico and California, seen brilliantly here at the Wedge, with long-period forerunners that spread across the Pacific at over 30 knots per hour. Photo: Dawson Maloney

Classic example of swell quickly meeting seafloor, as seen in New York. Photo: Matt Clark

Teahupoo. Photo: Tim McKenna

Wave speed is proportional to its period in deep water and to water depth in shallow water. For places like Teahupoo where the water goes from really deep to really shallow and quick - wave speed is somewhere in between a traditional deep water wave and a shallow water wave. So yes, the rumors are true that waves typically move faster at Teahupoo than they do at Virginia Beach. Photo: Ed Sloane

Australia. Photo: Jamie Scott