What's the biggest wave ever surfed?

As of 2013, the largest wave ever successfully surfed was a 100-foot wave ridden by professional surfer Garrett McNamara. McNamara caught this wave while big wave surfing in Nazaré, Portugal. Prior to this, McNamara had set the world record in 2011 by surfing a 90-foot wave in Nazaré.

McNamara has noted that this location in Nazaré is a particularly good site for catching big waves in record-breaking sizes. Apparently, the unique coastal geography in this area, which includes a massive underwater canyon and gigantic coastal cliffs, is responsible for the massive waves that break along the coast.