Port Blair, Nov. 7: Andaman & Nicobar Islands have undergone extensive hydrological changes with regard to coastal and underwater profile during the Tsunami in 2004.   Accordingly Andaman and Nicobar Command and Indian Navy have in the recent years made concerted efforts to carry out the hydrographical survey of the Islands to update charts of the area.  This will ensure safe navigation of all vessels plying in this region.

In pursuance of the updating of charts, INS Sandhayak and INS Darshak have conducted hydrographical survey off Andaman & Nicobar Islands in the month of Oct 12.  Sandhayak has conducted survey in the Eastern side of Middle Strait while Darshak has surveyed areas off Havelock,        Nancowry and Trinkat Islands.

Both the ships have gross registered tonnages of 1950 tones and a crew complement of 15 Officers and 150 Sailors. A variety of modern surveying equipments are fitted on these ships, which make them versatile platforms for a wide spectrum of survey tasks. The ships also carry an integral flight consisting of one Chetak helicopter which is used extensively as part of the survey operations and for Search and Rescue operations at sea.

The survey by the two vessels included conduct of depth soundings by the ship in deep waters and by survey motor boats in shallow waters, observation of tidal heights and streams, delineation of the coast line and inaccessible areas as well as analysis of nature of bottom.

The survey in the Middle Straits by Sandhayak has established depths of 10 to 20 mts inside the straits, which may be used for safe navigation by bigger crafts. The details would be available after the survey of the Western part of Middle Strait is conducted in early 2013 and of the charts get published by National Hydrography Office.