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Tl'n Kuroshio begins east of northern Luzon as a swift and narrow segmen! of lhe
western boundary curfent. IL flows close to Lhe east coast of Taiwan and then into the East
China Sea and farther north into the Japan Sea. At the height of the north monsoon' a
substantial mass of water from the Kuroshio is deflected into the China Sea and then pushed
farther south by the prevailing wind into the South China Sea and the Java Sea.
The Mindanao current flows souLhwards With a speed of I or 2 knots along the coast of
Mindanao Island. Its main part becomes the Equatorial Counter-Current. A weaker branch of
[he Mindanao current enters the Celebes Sea through the straits between Mindanao and
Sangir and Talaut Islands. Within the Celebes Sea, a major portion of its water is deflected
!o the soulh and flows along the north coast of Celebes as a coastal current to the east.
Tidal patterns
Next to waves and currents, tides are the mosL siriking feature of the movenents of
sea water, and they affect navigation considerably. The vertical movenents of sea water can
be transformed into tidal currents of high speed in narrow inlets, river mouthsr small bays'
and entrances to inland seas. Apart from the direct effect on ships, the dredging and silting
acLion in the waterways and harbour basins will affect conditions at the por!.
The tides of South-East Asian waters are affected by both lhe Pacific and the Indian
oceans. Thus, diurnal tides predcninate in the South China and Java seas, whereas mixed
tides prevail in the Eastern Archipelago and in Philippine watefs. However, semi-diurnal tides
of the Indian Ocean are predominant in the Andaman Sea and the shelf areas northwest of
Australia. Wyrtki (f961) characterized the four tidal types in the South-East Asian weters s
follows (Figure 4):
Figure 4 : Geographic distribulion of tidal types in South-East Asia