Epic ocean whirlpools created by the collision of opposing currents
The Onaruto Bridge connects Awaji Island in Hyogo Prefecture with Naruto City in Tokushima, one of four prefectures on the island of Shikoku. Underneath it, swirling as if part of a giant ocean vortex, is one of Mother Nature’s mysterious gems: the Naruto whirlpools. Whirling and whipping around as if giant plugs were pulled from the ocean floor, water appears to be draining through to the unknown depths below. The phenomenon occurs when opposing currents from the Seto Inland Sea and the Kii Channel meet in the Naruto Strait, a 1.3 km wide channel connecting the Pacific Ocean to the Seto Inland Sea. These powerful whirlpools form the point at which the large volumes of water and strong currents moving between the two oceans collide. Elusive on some days, and ever-present on others, the whirlpools vary in size depending on the intensity of the tides.