A rapidly developing hurricane-force storm low is forecast over the western North Pacific off the coast of Japan January 22nd-23rd with storm to hurricane force winds and significant wave heights to 17 meters (about 56 Feet). This will be a dangerous storm affecting ships arriving and departing Japan.
The highest significant wave height ever recorded was a massive 19 meters (62.3 feet!) measured by a buoy in the North Atlantic.
Hs or H1/3 = Significant wave height (average of the highest 1/3 waves)
H1/10 (Highest 10% wave height) = 1.27 x Hs
H1/100 (Highest 1% wave height) = 1.67 x Hs