The murky waters of the Ganga have emerged as a major hurdle in underwater search operations, prompting the Kolkata Police to shift focus from water drones to an advanced underwater communication system to improve rescue efforts, a senior officer said on Monday.
Trials have been conducted with water drones at several locations in the Ganga, but they failed to yield clear video footage due to the river's highly turbid water, raising doubts about the technology's effectiveness in real-life rescue missions, the officer said.
"The Ganga water is extremely muddy. Even when the drones descended several metres below the surface, the cameras could not capture clear visuals. It was difficult to see objects even a few metres away," the officer said.
In view of these limitations, the city police have decided to prioritise the procurement of an advanced underwater communication system that will enable divers from the Disaster Management Group (DMG) to stay in constant contact with their controllers on the riverbank during search and rescue operations.
The system will allow two divers to communicate with each other as well as with personnel stationed on the shore.
Officials said the communication will remain uninterrupted even when divers are wearing full-face masks. The system will use colour-coded communication ropes or cables linking the divers to the surface unit, while waterproof earphones and microphones will allow them to exchange messages clearly.
Special noise-filtering features will ensure that underwater disturbances, such as bubbles or ambient noise, do not interfere with communication.
"If a diver spots anything suspicious or faces any danger during an operation, the information can be immediately relayed to fellow divers and the control unit on the surface," another senior police officer said.
The Kolkata Police plan to spend around Rs 24 lakh to procure the underwater communication system. The equipment will be handed over to the Disaster Management Group.
Apart from the communication system, Lalbazar is also investing heavily in modern diving gear to strengthen underwater rescue capability.
Ten sets of advanced diving suits equipped with specialised masks are being procured at a cost of Rs 3.15 crore to enable divers to remain underwater for longer durations during operations. Officials said the suits will also help release toxic gases and improve underwater visibility.
To assist divers and carry out rescue operations on the river surface, the police are purchasing 20 rubber boats at a cost of about Rs 44 lakh. Each boat will have a seating capacity for five rescuers.
The force is also procuring 120 bright orange floating rings for the Disaster Management Group and river police units at a cost of around Rs 3,000 each.
Four paddle boats costing Rs 6 lakh in total are being added for rescue operations, with each boat capable of carrying two rescuers.
In addition, 70 life jackets are being purchased, along with five specialised hydraulic cutters designed to operate underwater.
According to officials, the cutters, costing around Rs 15 lakh, will be capable of cutting through submerged boats or watercraft at depths of up to 25 metres.
Police said the equipment procurement, costing nearly Rs 6 crore in total, aims to strengthen the city's capacity to respond to emergencies in the Ganga as well as in large water bodies across Kolkata.
