Surf wave height scale = Hawaiian scale

[Juzt1n]

Did ever why a 5ft wave is so massive with a wave face of about 9ft??? Well the system we use in surfing is called Hawaiian scale and is always quote in feet and is about 2/3 the height of the wave face. Some reckon its the wave height out at sea or the height at the back of the wave....

But actually ...
A long long time ago wave were always measured in "half-metres". So a 5"ft" wave (Hawaiian scale) is actually 5 half-metre wave and then some surf dude just thought a foot is about half a metre and called it a foot instead... So if you wanna calculate the wave height is real fts from hawaiian scale, just multiply by 3/2!