UZUSHIO KISEN

Uzushio Line carries passengers several times a day to the Naruto Whirlpools, a rare natural phenomenon in the Naruto Strait under the Onaruto Bridge. The strait marks the separation between the Japanese Inland Sea and the Pacific Ocean. The water rushes from the Pacific Ocean into the bay of Ōsaka and flows around Awaji Island to the Inland Sea of Japan before flowing down to the Naruto Strait. The water level will then be higher on the Sea of Japan side than on the Pacific Ocean side, cascading down to the Naruto Strait, with a water flow at a speed of 20 km/hour. The process will take 6 hours before it is reversed: it is then the water level on the Pacific Ocean side that will be higher. At the level of the strait, the current is very fast in the centre, but slower on the sides. It is this friction between currents of different speeds that produces the eddies. To observe these eddies when they are at their most spectacular, it is advisable to consult the tide schedules on the company's website. There you will find a table of schedules with the associated size of the eddies. Observation from a boat is a striking experience, especially when the eddies reach their maximum size.

Another company, Naruto Kanko Kisen, offers much the same. It is important to book in advance at ✆ +81 (0) 88 687 0101.