By Sunil Raman
BBC News, Delhi
Mumbai's police have acquired new craft to patrol the city's coastline
India is planning to secure its naval harbours with electronic fences, the BBC has learnt.
The fences are part of the Integrated Harbour Defence System to secure the harbours "against clandestine threat from sea", security officials say.
It is part of a plan to protect the country's coastline after November 2008's deadly attacks in Mumbai.
Ten gunmen had used boats to sail into Mumbai and carried out the attacks which killed over 170 people.
The Integrated Harbour Defence System will have diver detection sonars, high resolution radars with shore-based command and control system, among other things, officials said.
Radars will also be installed at distances of every 80km (50 miles) on the coastline.
The sonars and radars will pick up any movement near the harbour up to a distance of 70km (43 miles).
The electronic sea fences will be fixed on the sea bed close to a harbour to stop any diver or a boat from swimming or sailing through.
Only when a warship or a boat enters or leaves the naval harbour would the "electronic net" will be lifted for the ship to sail through.
Officials say India is also ordering sophisticated equipment to secure its 7,500km (4,660 miles) coastline dotted with nearly 200 ports.
The government plans to install transponders on every fishing vessel and trawler that sails into the high seas, officials say.
Mumbai alone has over 24,000 fishing vehicles, and Gujarat another 45,000 vehicles.
An Indian fishing vessel was hijacked in the seas off Gujarat by the gunmen who attacked Mumbai.
Former Indian intelligence chief Arun Bhagat is, however, sceptical about the measures to secure the coastline.
"The urgency which should have propelled state governments after the Mumbai attacks did not last long," Mr Bhagat said.
"Except for some states like Maharashtra and Gujarat, other coastal states have done little".