Vessel tracking systems

From Wiki.GIS.com

Vessel tracking systems are a voluntary system in which vessels mount a tracking satellite device on the vessel so that their movements, course, speed etc can be transmitted and analyzed from great distances – of great use in determining whether a ship or boat is in distress and or vectoring rescue assist actually in proximity to a casualty to them in a timely manner.

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2009)