Malaka

At approximately 500 miles long the Malacca Strait is the longest strait in the world that is used for international navigation. It forms the main seaway connecting the Indian Ocean with the China Sea and provides the shortest route for tankers trading between the Middle-East Asian countries. The greater part of the waterway runs through the territorial waters of Indonesia, Malaysia and Thailand with the much shorter Singapore Strait joining it at the southern end. It varies in width from 200 miles to 11 miles with irregular depths from over 70 to less than 10 meters. A through route of 23 meters depth have been identified.

There are numerous wrecks and shoal patches many of which are unconfirmed or their location reported in approximate position. Current predominantly flows in a north-westerly direction with rates of 1 to 1.25 knots but with the effects of tidal streams the speed of the flow increases to 5 knots in some localities.

Tidal range varies with locality from 1.6 to 3.7 meters, with much higher ranges inshore; Port Kelang, for example, experiences high water at spring tide up to 5 meters with the tidal stream attaining rates of over 4 knots. In the Singapore Strait tidal rate of 6 knots can be expected at some localities. Climate is tropical and the sea is generally calm but during the southwest monsoon and the two inter-monsoon periods occasional thunderstorms with squalls giving rise to winds gusting up to 50 knots may be experienced.

Rainfall is abundant and heavy rain can occur at any time of the year; the duration is generally short but intensities are high and often torrential. Visibility used to be good except during showers but haze has been a regular occurrence. In 1992 there was a prolonged period of thick haze reducing visibility to less than 1 kilometer.