Automatic Identification for Ships (AIS) is now compulsory on all vessels over 150ft. Although warships are excluded, they usually carry the equipment. Many small fishing boats do too.

Many leisure vessels carry AIS transmitters,,but the result in places like the Solent on a summer Saturday , where there could be several thousand AIS transmitters, is chaos. It may be that modified local regulations are needed to reduce the impossible clutter.

Without doubt AIS is the best addition to yacht safety on the last 25 years.

Marine Traffic developed by the University of Athens, is the best Internet display of AIS available. It has become the industry standard for commercial shipping and now accepts position reports via satellite, so is able to give a virtually worldwide view of shipping.

Using the Marine Traffic site enables all kinds of information to be viewed about the ship, its current position, course and speed;, type of cargo, ownership history, and so on.  You can play with the example opposite, or go to their main site and register as a user. I have done so, and posted some of my ship pictures where they add to the Marine Traffic library. Click on the button to visit the Marine Traffic site.