AIS ?????

Today we have a new page, AIS Location. What is AIS ? How does it work?

The Automatic Identification System is a short range coastal tracking system used on ships and by Vessel Traffic Services (VTS) for identifying and locating vessels by electronically exchanging data with other nearby ships and VTS stations. Information such as unique identification, position, course, and speed can be displayed on a screen on a vessel on software such as EXPEDITION, or streamed through the internet to a screen like yours.

The system works by each participating vessel having a transmitter which sends specially formatted messages by VHF radio. Once sent these messages are picked up by either massive land based receivers, such as used by Kordia, or by other ships. As with other VHF transmissions the distance a signal can be received is around the line of sight of the receiver antenna. This means the horizon that a container ship with antenna at 30m can “see” is much greater than what a yacht can “see” with antenna at 12m. Other factors that affect how far away AIS signals can be received is the power of the transmission, the environment between the transmitter and the receiver (yes that is my life’s work trying to understand) and of course how good the wiring is between the antenna and electronics on the boat.

There are two classes of AIS:

    * Class A – mandated for use on Safety Of Life At Sea Chapter V vessels – basically big ships

    * Class B – a low power, lower cost derivative for leisure and non-SOLAS markets. 

On Coppelia we have a Class B transmitter and receiver. This enables Rob and I to know where large ships and ferries are and hopefully big ships to know where we are. A bonus is that we using a vessel tracking service to show you where we are. So for the next race on August 14th you will be able to see where we are ever 6 minutes.