How big is that wave, really?
Surf reports and science measure waves differently, which is why a "10-foot" wave can be anything from waist-high to a building.
1.5 × a surfable beach break
3 m is taller than 4 of the 9 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| ripple on a lake | 0.1 m | 30× | |
| knee-high shorebreak | 0.5 m | 6× | |
| average man (US) | 1.75 m | 1.71× | |
| surfable beach break | 2 m | 1.5× | |
| big day at Pipeline | 6 m | 0.5× | |
| Mavericks | 18 m | 0.167× | |
| Nazaré record ride | 26.2 m | 0.115× | Sebastian Steudtner, 2020 |
| largest measured rogue wave | 29.1 m | 0.103× | The Draupner wave, North Sea, 1995 |
| Lituya Bay megatsunami | 524 m | 1/175 | Run-up height, 1958 |
Worth knowing
- The 1958 Lituya Bay wave stripped trees to 524 m up the opposite slope — the highest wave run-up ever recorded.
- The Draupner wave in 1995 was the first rogue wave measured by instrument, settling a century-old argument about whether sailors were exaggerating.
Frequently asked
Why do surfers and forecasters disagree about wave size?
Forecasts give significant wave height — the average of the biggest third — while surfers often quote the face height of the wave they ride, which can be twice as large. "Hawaiian scale" traditionally quotes the back of the wave, halving it again.
How big can an ocean wave get?
Wind waves are limited by fetch and duration; about 30 m is the practical ceiling. Landslide-generated waves have no such limit, which is how Lituya Bay happened.