Although the whirlpool of Naruto is justly famous, the rapid currents and whirlpools of the Geiyo Islands are little known but at least as impressive. The surface of the sea around the Shimanami Kaidō is roiled by rapid currents that flow like a river, due to the very high tidal difference of the Seto Inland Sea and the complex topography of its seafloor. This creates a constantly changing pattern of whirlpools on the surface when the tide turns. Fast motorboats leave from the north and south of Ōmishima Island, taking you right into the maelstrom to experience this remarkable natural phenomenon at close quarters. 

Boats depart from near the Murakami Suigun Museum in the north and from Iki-Iki-Kan at the southern end of Ōmishima.