Why the AIS technology was developed? For fun or to be useful?
AIS has been created ho help avoiding collisions between ships when they are at open sea far away from the shore-based systems.
Vessel tracking is needed most for ship owners to know at what location is their property in any time. For planning when the vessel will arrive at a port, when the vessel is moving and to calculate the time for the arrival. Tracking a vessel is helping the captains too, if they are aware of the exact position of the other ships they will know how to avoid collision, high traffic or danger areas.
Vessel tracking was stimulated after the 9/11 attacks on the U.S. Authorities quickly get the idea that a terrorist incident with vessels involved could have even bigger consequence. The ships aren't so well secured like planes or cars. Tracking all the time a vessel increases his security. There is one problem, AIS data is available for everyone. All with vessel tracking software could understand the exact location of the vessel with AIS transponder. Pirates are empowered with this information.
While ships have been obligated to install these new AIS communications techs to provide a vessel tracking system, the equipment and processes had to receive, estimate and disseminate this boom of info is years off from being entirely introduced by governments.
There have been developed Vessel Traffic Software receiving and working with the vessel tracking AIS data. Controlling the vessel traffic and making the accidents not happening became reality. Introducing the new technologies for tracking the vessels made the sea a safer place for the ships, people, cargo. Avoiding collisions is the primary objective, if you know where the other ships are, you can't hit them.
When incident occurs, vessel tracking systems help explaining why this happened. In the most cases the reason is the inconsistent speed of the ship.
Source:
vesseltracking.org 
