AIS considerations for a sailboat

Introduction to AIS

The AIS (Automated Identification System), is a system that allows to transmit the most relevant data of the vessel itself (position, course, speed, MMSI, name, etc.) and at the same time receive on board the data of the vessels that are around us (and that in turn encentren transmitting in AIS).

The AIS is mandatory on ships of a certain tonnage, and is gradually becoming an increasingly important equipment for pleasure craft, and personally I consider it a fundamental equipment on a sailboat as it significantly improves safety in navigation. On the one hand, if I have an AIS transmitter my boat will be visible to the boats around me, and on the other hand with the AIS receiver I will know well in advance the situation of the boats around me.

On a sailboat it is possible to install an AIS transceiver (or transponder), to transmit and receive AIS data, or only an AIS receiver (option I do not recommend), in which case my boat will not be visible in the AIS systems of the ships around me. There are several types of AIS (Class A, B and B+) that we will describe later, and we will compare their capabilities to see which is more suitable for our vessel, but without comparing specific brands or models.

On the other hand, the integration of AIS on board can be done in multiple ways. There are AIS equipment that have their own independent display screen, or that integrate the AIS data in other systems of the ship, such as a plotter (as the example we see in the figure of the Raymarine model plotter), a PC with electronic cartography, or a radar.

Another common option is a VHF radio, like the one shown in the figure above (right) from ICOM, which has an integrated AIS transceiver and display screen. In the figure below (left) we see an AIS Class B+ from Digital yatch, with wifi capability.

The AIS also has other utilities for a sailboat, and one of the most important is in the man overboard situation. If the shipwrecked person has an AIS radio beacon (on his lifejacket) his position will be known on board and this will facilitate his recovery. In the figure below (right) we see an Ocean Signal AIS together with two AIS beacons of the same brand.

In this chapter we will look in a little more detail, while avoiding too many technical aspects, at how AIS works, the AIS classes (A, B and B+) including a comparison of their characteristics, the importance of AIS in the “person overboard” situation, and some brief general considerations on the use of AIS on a sailboat.