American surfer Alessandro Slebir is believed to have conquered the biggest wave of all time, successfully riding an estimated 108-foot monster.

Slebir, 23, achieved the feat at Mavericks surf spot near Half Moon Bay, south of San Francisco.

Estimates have the wave at 108 feet tall, or just shy of 33 metres. The current official record is held by Sebastian Steudtner of Germany, who conquered an 86-foot wave (26 metres) at Nazare, Portugal in 2022.

Slebir cut from the top to the bottom of the wave, entering a massive barrel and safely exiting. It was a ride so good, so smooth that it would look great even on a smaller wave. The fact that he did it on a potential world-record-setting monster of a wave is all the more impressive.

Official confirmation of the record’s validity may take months, and will need to come by both the World Surf League, and Guinness World Records.

Steudtner’s record took approximately 18 months before it was officially verified by the necessary parties.

“It wasn’t like a decision of maybe we should go or not,” Slebir told CNN.

“Myself and my two partners, Luca Padua from Half Moon Bay, we knew right away we wanted it, said, ‘Grab the rope’ and he towed me, and the rest is now we’re here.

“You’re going so fast on those surfboards, you’re probably going 30, 40, 50 miles an hour [50-80kmh] and that wave was so tall that it was sucking so much water coming back at you that it was a weird feeling, feeling the friction of the water underneath the surfboard.

“I’ve never felt that on really any other wave that I’ve ever caught.”

The effort has already been said to be in discussion for the annual Big Wave Challenge.

Organiser Bill Sharp told Vice that while the estimation of 108 feet may not prove to be entirely accurate, he is confident the mark is within contention to set a new world record.