What AIS Is, How It Works, and Why You Should Have One

The most important thing to bear in mind when traveling by sea is safety. The most important means of enhancing safety is through knowledge and communication. One of the best ways to stay informed about the location of other ships is through AIS, or Automatic Identification System. This is also one of the easiest ways to discover the majority of relevant information that you need to know, as well as one of the quickest ways.

AIS is a system that surpasses radar by far in many ways. If you have an AIS receiver then you will be able to see where every other ship is, big and small. You will also be able to tell which direction they are headed and how big their ship is. But that’s not all. If you were to select one of the ship markers on the screen, you could tell where they were headed and how fast they were going. You would learn the name of the ship and their call sign, the ship classification and their registration number. Even though that is plenty of information, you could still learn other important facts that could help you navigate safely and in harmony with all the other vessels.

But how does this fascinating system work? Well, there are two AIS classes. Class A is reserved for larger ships while Class B is reserved for smaller ones. AIS requires a VHF transmitter, 2 VHF receivers, and a GPS receiver. A signal is sent out with all the information of the boat while at the same time all the other signals are being received, all on a VHF band. The VHF band can handle over 4,000 transmissions a minute, though it is rare when there is need for this much activity. Each transmitter reserves a series of transmission times that usually don’t overlap with other ships’ transmissions. Each transmission lasts for about 25 milliseconds. Currently, when you look at your AIS screen, the information will almost never be more than 2 seconds old. Someday, technology may advance enough to allow real-time read-outs.

It is wise to add AIS to your watercraft because it makes navigation so much safer. You will be able to see vessels when they are around peninsulas or on the other side of a big ship. This is something you wouldn’t be able to do with a radar. It also enables large commercial ships to see you more easily. This kind of communication is quick, simple, and important to you and everyone else out on the water. The only downside to the system is that it only works when people have it and use it. When people don’t have it, then a lot more work is required to make sure the plotted course is safe.