The water is sucked off a shallow, razor sharp reef, making the barrel break below sea level. "This wave is incredibly challenging to paddle into, let alone surf," notes Patterson. "Any mistakes could be costly."
The photograph was taken by a camera mounted to his board. Teahupoo is a village on the south-west coast of the island of Tahiti, French Polynesia, southern Pacific Ocean. It is known for the surf break and heavy, glassy waves offshore, often reaching 2 to 3 meters, and sometimes up to 7 meters.
Source: Wikipedia, National Geographic