How do we know?
↻ One of the pages with a moving picture
A floating buoy measured the biggest storm waves ever recorded.
- Wind blows across the sea. It rubs the water and pushes up ripples.
- The stronger the wind, and the longer and farther it blows, the bigger the waves grow.
- A wave is energy moving through the water. The water itself mostly goes round in small circles.
- Near the beach, a wave feels the seafloor, grows taller and breaks into surf.
A buoy rides up and down on every wave. A heave sensor inside measures how far it moves. Experts at the World Meteorological Organization checked the record.
On 4 February 2013, a floating buoy in the North Atlantic, west of Scotland, measured the record storm waves. The biggest waves were averaged to get the number.
In October 2020, a surfer rode a wave at Nazaré, Portugal, about 86 feet tall: the biggest wave ever surfed!
Wow number
62 feet is the record height of big storm waves measured by a floating buoy. It happened in the North Atlantic Ocean on 4 February 2013.
Myth or fact?
A tsunami is a kind of tidal wave. Myth. Tides have little to do with tsunamis.
In deep water, a tsunami can travel as fast as a jet plane. Fact. It slows down near the shore.
Think about it
Why do you think the waves are often bigger on a windy day?
Where in the world?
Nazaré, Portugal where a surfer rode a wave about 86 feet tall in October 2020, the biggest wave ever surfed. The record storm waves were measured by Buoy K5 in the North Atlantic, west of Scotland — 39.6021° N, 9.0713° W.
Where these facts come from
Every number on page 41, and who measured it
This page explains how wind makes waves, and how water moves in circles as a wave passes.
Why does the ocean have waves? — NOAA's Ocean Service, U.S. ocean scientists
oceanservice.noaa.gov/facts/wavesinocean.html
We checked it on 31 October 2026
This page tells us how waves break into surf near the shore.
Waves — NOAA, the U.S. weather and ocean agency
noaa.gov/jetstream/ocean/waves
We checked it on 31 October 2026
This official world-records page lists the 62-foot wave measured by Buoy K5.
Global: World's Highest Significant Wave Height (by Buoy) — The World Meteorological Organization, the United Nations' weather agency, which keeps the official world weather records
wmo.int/asu-map?map=Wave_070
We checked it on 31 October 2026
This page also lists the 2013 buoy wave record.
Highest significant wave as measured by a buoy — Guinness World Records, which keeps lists of world records
guinnessworldrecords.com/world-records/460263-highest-significant-wave-as-measured-by-a-buoy
We checked it on 31 October 2026
This page tells us about the biggest wave ever surfed, at Nazaré.
Largest wave surfed (unlimited) - male — Guinness World Records, which keeps lists of world records
guinnessworldrecords.com/world-records/78115-largest-wave-surfed-unlimited
We checked it on 31 October 2026
This page tells us the giant Nazaré wave was surfed in October 2020.
Sebastian Steudtner surfs giant wave and smashes world record — Guinness World Records, which keeps lists of world records
guinnessworldrecords.com/news/2022/5/sebastian-steudtner-surfs-giant-wave-and-smashes-world-record-705874
We checked it on 31 October 2026
This page tells us that tsunamis are not tidal waves, and how fast they can travel.
What is a tsunami? — NOAA's Ocean Service, U.S. ocean scientists
oceanservice.noaa.gov/facts/tsunami.html
We checked it on 31 October 2026
Has this changed?
How waves form is not going to change.
Records can be beaten. The 62 feet is the record so far for a buoy, and the biggest wave surfed so far.
Words from this page
- surf
- Waves that have broken near the beach.
- buoy
- A floating marker with instruments that measures the sea.
- tsunami
- A giant wave, usually made by an underwater earthquake. It has nothing to do with the tides.
Try it!
Watch a cork bob while ripples pass.
1. Float a cork or a bottle cap in the middle of a sink or tub of water. 2. Tap the water at one end with your finger again and again. 3. Watch the cork as the ripples pass it.
What happens: the ripples travel across, but the cork mostly bobs up and down in place. Waves move energy, not the water!
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