Joint Hydrographic Survey in the Straits of Malacca and Singapore

Abstract

The four nations of Indonesia, Japan, Malaysia and Singapore carried out jointly the hydrographic survey of the shipping route through the Straits of Malacca and Singapore with a view to securing navigational safety in the Straits.
(1) Preliminary hydrographic survey.
In 1969, a preliminary survey was conducted on four sounding lines with the spacing of 1 kilometre along the shipping route through the Straits. The purpose was to obtain necessary information for determining those sea areas where detailed hydrographic survey would be required, as well as to investigate performances of various survey instruments to be used in the detailed survey. Incidentally, the survey revealed that sandwaves developed in the area and that there existed 21 uncharted shoals of less than 23-metre deep which might present danger to huge vessels' navigation.
(2) 1st detailed hydrographic survey.
Of the areas where detailed survey was necessitated by the results of the preliminary survey, those in the Main Strait and Phillip Channel and their adjoining waters were survey in detail in 1970. As the result, 30 uncharted shoals were revealed to exist. It was also found that discrepancies existed between the geodetic systems of Malaysia and Indonesia, i.e. about 60 metres in south-north and about 400 metres in east-west directions.
(3) 2nd detailed hydrographic survey.
In 1972, the 2nd detailed hydrographic survey was conducted in the area western continuation to the survey area of the 1st detailed survey and in the areas off Cape Rachado. Neither any dangerous uncharted shoal nor data indicating shift of sandwaves formerly disclosed by the preliminary survey was found by the survey. However, a sunken wreck with a least depth of 14.9 metres over it was found amid the shipping route.