Naruto Whirlpools

What to know

The Naruto Whirlpools (鳴門の渦潮, Naruto no Uzushio) are a dramatic natural spectacle along the Shikoku coast of the Naruto Strait. They form when massive volumes of water rush between the Seto Inland Sea and the Pacific Ocean during tidal changes, amplified by the strait's unique underwater topography.

These whirlpools appear roughly every six hours, typically once in the morning and once in the afternoon, lasting one to two hours. Their size varies with tidal intensity—larger in summer than winter, and biggest during spring tides, which occur every two weeks when the sun, Earth, and moon align.

Under ideal conditions, whirlpools can reach up to 20 meters in diameter. However, on calm days or outside peak times, there may be little to see. So it's essential to check the whirlpool schedules (see links below) when planning your trip to Naruto.

The whirlpools are safe for boats and best viewed from sightseeing cruises that get you right next to the action. Two companies operate from piers on Shikoku, and one from Awaji Island on the opposite side of the strait.

On the Shikoku side, Uzushio Kisen runs small boats with water-level decks from a pier just outside Naruto Park. A bit farther away, Uzushio Kankosen offers the "Aqua Eddy" (medium boats with two decks and underwater windows) and "Wonder Naruto" (large boats with two decks).

For the best views, consider the "Wonder Naruto" boat tour, which provides excellent vantage points from its upper first-class deck (at an extra charge). Tours last 20–30 minutes and depart about twice per hour.