On the 18th day of the operation, the navy divers stayed inside the shaft for three hours with a hi-tech gadget, Under Water Remotely Operated Vehicle (UWROV), and found visibility to be very poor – only one foot. The search would be feasible only after the water level inside the shaft is reduced to a safe diving limit of 30 metres. The depth of water is expected to be over 150 ft.from Guwahati News, Latest Guwahati News Headlines & Live Updates - Times of India http://bit.ly/2VlXUMQ