Jeff Rowley cc
On January 28, remarkable photo and video footage appeared that showed 45-year-old Hawaiian Garrett McNamara sliding down a mammoth peak at Nazaré, Portugal. That wave was generated by a barocyclonic low that swept across the Atlantic and focused powerful swells into Nazaré's deep submarine canyon.
Within hours there were reports that the wave might have shattered McNamara’s own record of 78 feet to reach a sky-scraping 100. But how are record waves measured?