A surfer from America has had his claim for a new world record confirmed - for surfing the biggest wave ever.
Back in November Garrett McNamara was in a competition on the coast of Portugal, when a massive wave built up behind him.
He managed to stay on his surfboard despite the wave crashing into him.
At the time, estimates were that Garrett's wave was about 30m high - that's the same as five houses or 15 tall men - but it was actually 24m.
"Everything came together. Everything felt right," said Garrett, who started surfing when he was just 11-years-old.
Experts who measure surfing waves looked at his video footage and concluded it was indeed a world record.
Judges went to extraordinary lengths
Garrett has now won a cash prize for his achievement - around £10,000 - at an award ceremony in California.
Judges for the awards examined the footage and pictures from different angles.
They even measured his height when in a crouching position, the length of his shin bone, AND the top and bottom of the wave.