Summary
NUMAZU
NUMAZU OPERATING AREA
SUMMARY
The conclusion reached in this study is that Suruga Bay, including the Numazu Operating Area should not be considered a "safe" typhoon haven for ships operating in the area or transiting the south central coast of Honshu. The primary factors in reaching this conclusion are:
(1) The openness of the bay to the effects of the ocean -- especially in the southwestern quadrant.
(2) The lack of any suitable sheltered area for a ship to lie to or anchor in.
(3) Wind and swell wave action can be as devastating in the Suruga Bay area as on the open ocean if these effects are being felt from the south-southwest. (A southwesterly wind gust of 97 kt was recorded at Numazu on 25 September 1966 as Typhoon Ida passed 30 n mi to the west. Winds in excess of 34 kt existed for 5 hours.)
Some protection from northeasterly winds (associated with a tropical cyclone passing to the east) may be found by keeping close to the Izu Peninsula (eastern) side of the bay. This should reduce the effects of the wind and wind generated waves because of the shorter fetch the winds would blow over. In spite of the deep water in Suruga Bay, caution should be exercised when operating close to land as visibility may be reduced and radar reception hindered by the effects of a tropical cyclone passing close by. Also the confused sea state with accompanying wind may set up unpredictable local currents.
Additionally, it has been concluded that surf conditions in the Numazu Operating Area may be unsafe for small craft operation for a number of days after a tropical cyclone passes CPA because of the slow decay rate of swells associated with such a storm. This conclusion can also be applied to tropical cyclones, especially typhoons, that pass well to the south of the 180 n mi threat circle used in this study.
To avoid the effects of tropical cyclones that pose a threat to the Numazu Operating Area, evasion to the Yokosuka/Tokyo Bay area ishighly recommended.
Source: http://www.nrlmry.navy.mil/port_studies/thh-nc/japan/numazu/text/summary.htm
