The question of the “biggest wave ever recorded” does not have a single, simple answer because the term “wave” is defined and measured differently across various contexts. The largest waves are categorized by their formation mechanism, which determines whether they are measured by their destructive run-up height, their crest-to-trough height in the open ocean, or their rideable face height. This ambiguity means the record holder shifts depending on the criteria used. The world’s record waves can be divided into three distinct categories: megatsunamis, open-ocean giants, and towering surfable walls sought by athletes.
The Undisputed Record: Megatsunamis
The most immense wave event in modern history, measured by its impact elevation, was a megatsunami that occurred in Lituya Bay, Alaska, on July 9, 1958. This event was not a typical seismic tsunami caused by tectonic plate movement, but rather a localized, massive “splash” event. The initial trigger was a magnitude 7.8 to 8.3 earthquake along the Fairweather Fault, which destabilized the steep slopes of the fjord.
The actual wave was generated when a colossal rockslide, estimated to be about 40 million cubic yards of rock and glacial ice, plunged nearly vertically from approximately 3,000 feet into the narrow inlet of Gilbert Inlet. This enormous mass striking the water created a violent and sudden displacement, pushing the water column upward. The water surged up the opposite side of the inlet, registering a final run-up height of 1,720 feet (524 meters).
Run-up height is the vertical distance the water reaches above sea level on a slope, and this measurement stripped the soil and vegetation from the hillside up to that extreme elevation. The power of the subsequent wave that moved down the bay was still destructive enough to sink boats and flatten forests. This type of event is distinct from a seismic tsunami, which carries energy across entire ocean basins. A megatsunami is a localized phenomenon with an overwhelming initial wave height, making the 1958 Lituya Bay wave the highest measured water mark in recorded history.
Open-Ocean Giants: Storm and Rogue Waves
Beyond the coastlines, the largest waves encountered in the open sea are classified as either extreme storm waves or rogue waves. These open-ocean giants are measured by their crest-to-trough height above the mean water level, recorded by instruments like buoys or laser altimeters on offshore platforms. Rogue waves are defined by oceanographers as waves that are more than twice the height of the surrounding “significant wave height,” which is the average height of the largest one-third of waves in a given sea state.
The most famous instrumentally recorded rogue wave is the Draupner wave, detected on January 1, 1995, at the Draupner gas platform in the North Sea. This wave reached a maximum crest-to-trough height of 25.6 meters (84 feet), emerging suddenly from a sea state where the significant wave height was much lower. Rogue waves often form through constructive interference, where multiple wave trains traveling at different speeds align their crests at a single point in space and time.
This simultaneous alignment compounds the energy of the individual waves, creating an unexpectedly large, steep wall of water. Such waves pose a severe threat to large vessels and offshore infrastructure because of their unpredictability. The Draupner wave was the first to be officially confirmed by a measuring device, shifting rogue waves from maritime folklore to a subject of serious scientific study. Modern satellite altimeters now regularly detect these extreme events in remote ocean regions, confirming they are a regular, though rare, feature of the open sea.
The Human Element: Surfing the Biggest Waves
A different measure of a wave’s size focuses on the largest wall of water successfully ridden by a human surfer. These are gravity-driven surface waves, often generated by powerful North Atlantic storms, but their massive size is amplified by specific underwater topography. The record for the largest wave ever surfed is currently held by Sebastian Steudtner, who rode a wave measured at 86 feet (26.21 meters) at Praia do Norte, Nazaré, Portugal.
The waves at Nazaré are dramatically magnified by a deep underwater canyon, the Nazaré Canyon, which funnels and accelerates incoming swells toward the coast. The canyon’s geometry forces the wave energy to compress and stack, creating exceptionally tall, breaking waves that are rideable. Due to their immense size and speed, these waves are typically surfed using a technique called tow-in surfing, where a surfer is towed onto the wave by a personal watercraft.
The official measurement and ratification of these records are conducted by organizations like the World Surf League, often using photogrammetry and video analysis to precisely calculate the distance from the trough of the wave to the crest as the surfer is riding it. Steudtner’s record ride, which took place on October 29, 2020, represents the limit of human performance and technological aid in mastering the ocean’s largest moving surface waves. The height of a surfable wave is defined by its vertical face, a measurement distinct from the crest-to-trough measurement used for open-ocean rogue waves or the run-up height of a megatsunami.