Underwater map of Mavericks surf spot

Mavericks is a world famous surf spot just south of San Francisco near Half Moon Bay. Known for insanely massive waves that can top out at 50 feet or higher, Mavericks is home to incredible big wave surf competitions and was the death of legendary Hawaiian surfer Mark Foo. Only now though have geologists discovered exactly why Mavericks delivers such magnificent waves. Researchers at the US National Oceanic and Atmospheric Administration bounced sound waves and light off the seafloor to generate a high-resolution 3D map of the underwater terrain. According to the researchers, "the abrupt topography of the bedrock reef at Mavericks causes wave energy to converge over the reef, causing the wave to rapidly slow down, shorten in length and substantially increase in height." From New Scientist:
Mavericksmap-1 “As soon as I saw that gradual ramping from deep to shallow water, it was, like, wow! That’s why Mavericks happen,” says Rikk Kvitek, director of the Seafloor Mapping Lab at California State University in Monterey Bay. “I’ve done an awful lot of seafloor mapping and I’ve never seen geology like that before.”

As waves get close to shore, their base begins to run into the seafloor, slowing the deeper parts of the wave. The shallower part of the wave keeps moving at the same pace, causing the wave to stand up and then pitch forward. This creates the wave face that is so sought-after by surfers.
Link to New Scientist article, Link to High Resolution Mapping of Mavericks project