What is AIS?

The Universal Shipborne Automatic Identification System is a system of transponders installed on vessels which transmit over two dedicated digital marine VHF channels. The data is sent from each vessel every few seconds and contains position and movement information such as course, speed, latitude, longitude, and rate of turn. Static information about the vessel is sent every few minutes and includes the name, type of ship, length, beam, draft, etc.

Nearly all commercial ships are mandated to carry AIS transponders and each year more yachts, launches and work boats are fitting AIS transponders. You can receive this data with an AIS receiver which translates the digital radio signals or you can receive as well as send your own information with a transponder. There are two types of transponders, Class A intended for SOLAS vessels and Class B for fitting on non-SOLAS category vessels.

Also for another excellent introduction to AIS, take a read of this article, How AIS Can Improve Your Navigation & Safety. It's written by Tim Bartlett who is acknowledged as a worldwide authority on marine electronics.  This article was published in the March 2011 Yachting Monthly magazine.  It answers some of the most asked questions about AIS like;

• Can ships filter out Class B AIS?
• Is AIS complex to use?
• Is AIS useful on a yacht?
• Is AIS Class B as powerful as AIS Class A?
• Do all ships use AIS?
• What is the benefit of the target list?
• What is the benefit of a separate AIS display versus an AIS data box?
• What is the benefit of the graphic display?
• How do I know if they have seen me?
• How do I install AIS?

The AISWatchMate is the ideal display and collision warning alarm for use with either receivers or Class A or B transponders.

For a fully integrated receive-only solution use the AISWatchMate RX. It includes a built-in high performance two-channel AIS receiver. It's highly sensitive parallel receivers provide greater range and increased safety. There are no external "black boxes" to fit and it provides full AIS output to other on-board electronics.

For the ultimate transmit and receive solution, use the AISWatchMate Transponder. This innovative product combines our award-winning display capabilities with a built-in Class B AIS transponder, GPS and GPS antenna. There are no external boxes to install. Just give it power and plug in an antenna. It's the best dedicated AIS collision avoidance solution available. You'll see all other AIS-equipped vessels and be seen by them too.