Garrett McNamara surfs 'highest ever' wave off Portugal
An American man has ridden what may be the highest wave ever caught by a surfer.
Garrett McNamara surfed the wave on Monday off the coast of Portugal, in the same spot where he surfed the current world-record wave of 78ft (24m) in November 2011.
Experts will now have to certify the new record.
The giant wave formed above an underwater canyon famous for being the world's biggest wave generator.
Some reports say the wave may have been as high as 100ft (30m), although this is yet to be confirmed.
"You are just going so fast," McNamara told ABC television. "It's really, really similar to snowboarding on giant mountains.
"And you're just chattering, flying down this bumpy, bumpy mountain. Your brain is getting rattled. Your whole body is getting rattled."
He said he was relieved to have avoided a rocky section of the coast.
McNamara began surfing at 11 and turned professional six years later.
Swell waves can travel thousands of miles across the Atlantic from as far west as the Caribbean.
The Nazare Canyon, which is an underwater valley the size of the Grand Canyon, helps concentrate the waves’ energy.
As the water becomes more shallow, the waves slow down while maintaining their energy, so they become bigger. The gradient of the shoreline at the head of the canyon is ideal for producing plunging breakers which surfers love. (Video clip is of McNamara breaking the world record in the same spot in November 2011.)