Whirlpools
The whirlpools of the Naruto Strait are famed for their size and power, and for their diverse forms. These features are due to a natural tidal phenomenon unique to Naruto.
The whirlpools take on some characteristic patterns. Uzutsui are “whirlpool pairs” spinning in opposite directions on either side of the stream that speeds southward through the center of Naruto Strait. Yusho-uzu, or “whirl-flowers” are large disc-shaped masses of water shaped by an upward flow resulting from the complex shape of the sea bed; they occur close to the strait’s narrowest point. Uzuren (“repeating whirlpools”) is perhaps the most spectacular formation. Rows of as many as seven whirlpools form simultaneously, with each new one surfacing before the preceding ones have disappeared (Naruto’s whirlpools typically last for 20 to 30 seconds each).
Since long ago, people were captivated from afar by depictions of the Naruto whirlpools in ukiyo-e woodblock prints by artists such as Utagawa Hiroshige (1797–1858). Though their spectacle can be enjoyed all year round, the whirlpools reach peak intensity in spring and fall. They are particularly powerful at the new moon and the full moon, when the tide is at its strongest.