Automatic Identification System or AIS as it is commonly known, is a VHF based ship identification scheme that has been used since the year 2000. It is a compulsory prerequisite for ships over 300GT bound for international voyages. The AIS system has been verified to be a advantage for collision avoidance amongst crafts and is as well extensively used in assisting Vessel Traffic Services (VTS).
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Recent advancements in this equipment have marked the introduction of virtual AIS. Virtual AIS is founded over the model of Pseudo AIS messaging. Pseudo AIS is fundamentally an AIS message transmitted by means of VTS centers to provide ships with information about towing vessels and other such ships that do not have AIS equipment. The VTS centre puts out a pseudo AIS message on behalf of the towing craft, to ships in the area in order to provide the towing vessel a wide approach margin.
This idea of pseudo AIS has taken another step forward by initiating the employment of Virtual Buoys and Virtual Pilotage. Virtual Buoys are essentially AIS messages dispatched by the VTS or Port Authorities to sea crafts in the docks, giving out the information on navigational buoys that aren’t really present. Sea crafts that are en suited with AIS transponders can use this data to steer their way safely through tight channels and avoid hitches. This system is exceptionally lucrative because the fixed cost required with installing and maintaining a physical buoy is eliminated. It is also advantageous to navigation because the buoy will appear on AIS-linked radar screens regardless of the degree of visibility or weather conditions.
One excellent example of a successful Virtual Buoyage system is in the Hooghly River in India wherein the river banks keep changing because of silting. This makes the makes the maintenance of buoys very difficult since they have to be moved around very often to signify the demarcation lines of the bank’s new position. This impediment has been successfully surmounted with the help of a Virtual Buoy system to mark the channel.
