GUWAHATI: As a team of deep divers from the Eastern Naval Command in Visakhapatnam engaged in tracking the ill-fated Swift D’Zire and its occupants – five of a family – toiled hard in vain over and under the muddied waters of the Dikhow river on Tuesday, there was optimism that a sophisticated machine, mostly used in underwater sea operations, would help locate the vehicle.
The weather too had cleared as the team took resort to the Side Scan Sonar (sound, navigation and ranging), an advanced equipment generally used by the Navy to track metallic objects under water, to locate the vehicle which had skidded off an embankment at Dechial village in Upper Assam’s Sivasagar district on the evening of September 1.
“The Side Scan Sonar is used by the Indian Navy across the country for operations such as repair of vessels under water and locating metallic objects. Its technology however is changing over the years. However, I cannot say when such a machine was last used by a diving party in the Northeast,” a defence spokesperson based in Kohima told The Shillong Times on Tuesday.
The side scan sonar creates a picture or an image of the sea floor. It measures the strength of how “loud” the return echo is, and paints a picture. The sonar imagery is also a commonly used tool to detect debris and other obstructions on the seafloor that may be hazardous to shipping or to seafloor installations. Scientists use the sonar for mapping the ocean floor.
“However, in case of this particular river (Dikhow) which is narrow and relatively wider in stretches, there may be a natural inlet where the vehicle may be stuck and therefore difficult for the rays emitted by it to hit the metallic object,” he said.
“However, if it was a case of tracking people who are feared drowned then the machine is not used as it can track only metal or hard objects,” the defence spokesperson added.
As it is, rain coupled with high undercurrent and muddy waters of the river had affected search operations as teams of NDRF, SDRF and Army were deployed since September 2.
The 10-member Navy team thereafter arrived on Monday afternoon to carry out search operations using advanced equipment.
Sources at the Visakhapatnam-based Eastern Naval Command too could not confirm whether the side scan sonar was used for the first time in the Northeast.
