Coast Guard officials say that mechanised fishermen will find the system invaluable in distress situations at sea, and have handed over five of the transmitters to fishermen operating mechanised boats in Chennai.

The Coast Guard's demo is being carried out after a series of extensive field trials by the guardian of India's coastal waters along with ISRO.

The transmitter can be installed snugly on the main mast or sailboat aft, though the venture is being tried out for a start with mechanised boats.

Emergency alerts can be sent by fishermen to report their position to the Coast Guard and state government authorities in case of emergencies caused by ill-health or inclement weather on their vessels, fires on board, sinking or capture by pirates.

Alerts sent by the inbuilt GPS transmitter indicating the boat's ID, position at sea, type of emergency, and time of alert activation will be received by INSAT 3A and forwarded to the Coast Guard's regional headquarters in Chennai where a Alert Reception Centre has been set up. Alerts will also be picked up by the Maritime Rescue Coordination Centre in Chennai.

The transmitter operates through a DRT transponder and can send out continuous alerts for 24 hours once every 5 minutes on an average while the staff at the rescue centres track the boat as it appears on a GIS map on their computer screens.

Each transmitter costing below Rs 10,000 with an omni-directional antenna, has a lithium battery life of 24 to 48 hours after activation and will give its number and GPS position of the boat to the Coast Guard, which can then swing into action and carry out mid-sea rescues. As for the much harried fisherman, he need fear no more about being all at sea on his location while on the job.