TidesandCurrents
YOKOSUKA
TIDES AND CURRENTS
The effect of the current in the vicinity of O Shima is greatly modified by the tidal currents. The East Kuroshio impinges on the island in the vicinity of Semba Saki, the southwest extremity of the island, and divides, with one branch flowing north along the west coast, and the other flowing east along the south coast. The north branch flows northeast past Chiga Saki, the island's northwest extremity, at a rate of about 3 kt. Tidal rips occur here. The south branch flows east past Habu Ko, at a rate of 3 kt, but during spring tides in the summer, a resultant west set has been observed during the flood. Tidal rips occur off this southeast point. Off the east side of O Shima, the flood sets north and the ebb sets south at respective rates of 0.5 and 1.5 kt.
In Uraga Suido, the tidal currents set generally north on the flood and south on the ebb. They are greatly affected by the wind.
The tidal currents in Tokyo Wan are weak and irregular and are usually stronger on the west side than on the east. In the narrows between Futtsu Saki and Kannon Saki, the flood sets northwest and then follows the trend of the shore to Yokohama ; the ebb sets in the opposite direction. At springs, a drift of 1 to 1.5 kt is experienced.
As of the Site Visit in November 2005, the Pilots stated that an approximate1.5 kt current had been experienced outside Yokosuka Harbor and less than 1 kt inside the Harbor.
The mean range of the tide at Yokosuka Ko is 3.2 ft, and the spring range is 4.3 ft.
Source: http://www.nrlmry.navy.mil/port_studies/thh-nc/japan/yokosuka/text/sect6.htm
