South East Asia post-tsunami water depths

One of the unseen consequences of the recent earthquake off the western tip of Sumatra and the resultant tidal waves MAY be a change of water depth as a result of sand waves created by the tsunami, particularly in the Malacca Straits, warns the Marshall Islands Registry. It urges all ship owners to observe any depths that may have changed and to make the appropriate reports for the benefit of the shipping community in general.

It recommends the following procedures:

1.       Listen for broadcasts of changes in depths from shore stations and report them to your DPA immediately.

2.       Turn on the ship's echo sounder recorders during transits through the Straits, especially in the vicinity of One Fathom Bank, carefully marking times on the recorder paper together with GPS positions, and note any depths less than charted.

3.       Advise VTS traffic control of any depths less than charted.

4.       Notify hydrographic services directly of any depths less than charted. As a reminder, Marine Notice 7-041-3, Hydrographic Information: Cooperation with Hydrographic Services, provides guidance on reporting changes in aids to navigation and other Hydrographic data.

5.       Consider broadcasting a SECURITY message if serious reductions in depths are noted.

The Maritime and Port Authority of Singapore (MPA) is also concerned with navigational safety in the Straits. To date, it has not received any reports on changes to charted depths from vessels transiting the MalaccaStrait, in particular the One Fathom Bank area. There has also been no report of damaged or missing aids to navigation.

It concurs with recommendations for vessels transiting the MalaccaStrait to keep a vigilant watch and to report any changes to depths or aids to navigation to the relevant authorities. The MPA will immediately issue navigational warning broadcast on changes to depths or aids to navigation that may affect navigational safety in the Straits.

In the meantime we recommend that members with vessels proceeding in South East Asian waters, or intending to fix their ships or load cargo for such destinations, act prudently and verify port and channel conditions for themselves.

Contacts: Howard Snaith,John Fawcett-Ellis