A red volcanic cone on a dark blue sky, a breaking wave in a stormy sea — Katsushika Hokusai's vivid depictions of Mount Fuji have become iconic for Japanese art. At seventy years of age, Hokusai began the work on Thirty-Six Views of Mount Fuji (Fugaku sanjurokkei), his masterpiece, in 1830. The woodblock print series actually consists of forty-six views of the mountain, the other scenes bearing Hokusai's new signature and being printed almost entirely in shades of Prussian blue. The Great Wave off Kanagawa (Kangawa oki nami ura) is the central piece of Hokusai's celebrated series, and of an exhibition at the Art Institute of Chicago (Beyond the Great Wave: Hokusai's Images of Mount Fuji, 20 July–6 October 2013).

Hokusai's Great Wave is very realistic and there is more to it than first meets the eye. It is not a tsunami as many might have thought. A recent study (J. M. Dudley, V. Sarano and F. Dias, Notes Rec. R. Soc. 67, 159–164; 2013) suggests that it is a rogue wave — a very rare phenomenon caused by the combined effect of winds and ocean currents. Rogue waves occur spontaneously and are much larger than any other wave close by. By contrast, tsunamis refer to a massive water displacement propagating as a linear wave, and are created by a sudden movement of the ocean floor.

Both tsunamis and rogue waves are dangerous natural phenomena, but for ships far out at sea tsunamis do not represent a threat, whereas unpredictable rogue waves do. But, the oshiokuri boats in Hokusai's Great Wave may not be so vulnerable after all. This is because of the strong localization that could arise from linear propagation effects. Photographs of subantarctic waves show very similar localization and breaking dynamics. An alternative explanation for the characteristics of the Great Wave invokes solitons (J. H. E. Cartwright and H. Nakamura, Notes Rec. R. Soc. 63, 119–135; 2009), but the role of linear and nonlinear effects in the formation of rogue waves remains controversial. Perhaps the absence of a complete understanding of the underlying physics makes the art more mysterious and allows us to enjoy it even more.