Naruto whirlpool
The Naruto whirlpool is a tidal whirlpool in the Naruto strait, a channel between Naruto in Tokushima and Awaji Island in Hyogo, Japan.
The strait between Naruto and Awaji island has a width of about 1.3km. The strait is one of the connections between the Pacific Ocean and the Inland Sea, a body of water separating Honshu and Shikoku, two of the main islands of Japan. The tide moves large amounts of water into the inland sea twice per day, and also removes large amounts of water twice a day. The tide has a range of up to 1.7m, creating a difference in the water level of up to 1.5m between the inland sea and the Pacific. Due to the narrow strait, the water rushes through the Naruto channel at a speed of about 13-15 km per hour four times per day, twice flowing in and twice flowing out. At the maximum tide of the year, the spring tide, the speed of the water may reach up to 20 km/h, creating a vortex up to 20m in diameter. The current in the strait is the fastest in Japan and the third fastest in the world after Moskstraumen of Norway with a top speed of 27.8 km/h and the Old Sow between New Brunswick and Maine with a top speed of 27.7 km/h.
The whirlpools can be observed from ships, or from the Ohnaruto bridge spanning the strait. The suspension bridge has a total length of 1629m, with the center span over the strait having a width of 876m and a height of 41m above sea level. A good observation is also possible from the shore on Awaji island.
