Shikoku

Shikoku is Japan's smallest main island, with its north coast facing the Seto Inland Sea and its south coast open to the Pacific. The Seto Inland Sea side has semidiurnal tides with spring ranges up to 2.5 m and powerful currents in the narrow straits between islands — the Naruto Strait whirlpools near Tokushima reach 20 km/h at peak spring flow. The Pacific coast at Kōchi faces open ocean with spring ranges around 2.0 m and direct typhoon exposure in summer. Shikoku's tidal straits are among the most technically demanding coastal passages in Japan for small-boat operators. The island's Buddhist pilgrimage circuit — 88 temples over 1,200 km — crosses coastal headlands and fishing villages; the sea is a constant companion for pilgrims walking the southern stages. Bonito (katsuo) fishing is central to Kōchi's food culture: the tatakami-style seared bonito served in Kōchi's Hirome Ichiba market comes directly from the waters off the Pacific coast.