The automatic identification system, also known as AIS is an automatic tracking system which allows vessels to exchange data pertaining to their course, speed, and position. For smaller boats, it is mostly used to avoid any potential collisions. AIS is a digital VHF radio-based transponder system with precise position information. This system is like digital radar, using GPS, VHF radio and advanced digital processing to transmit information between vessels.
AIS works by using GPS and VHF radio to broadcast a ship’s information, including the speed and heading, the name of the ship, port of origin, size of the vessel, and even more. This information is constantly updated and can be seen by any other vessel equipped with an AIS unit. Any boater can download an app to view ships connected to AIS, however, their location will not be shown. AIS is broken down into two classes to determine the level of system needed for the boat or ship.
Class A units have a range of 20 to 30 miles and have a dedicated screen for broadcasting, updating ships’ locations every two to ten seconds underway and every three minutes while at anchor. These stand-alone systems are the most expensive, costing on average between $2,000 and $3,000. Ships that require Class A units are over 300 tons and 65 feet and travel internationally, and are also used for passenger ships and most commercial vessels.
Class B units are similar to a “black box,” using your electronics and displays on your networked MFD. This class is geared more towards recreational boaters and cruisers that may find themselves in congested harbors. This Class B system will transmit positions of vessels every 30 seconds, and every two minutes if you are moving slower than two knots. You will be able to “see” any vessels that also use AIS and they will be able to “see” you. This system ranges between $500 to $1000 on average.
The least expensive option to harness any AIS data is from a computer or an app. There are plenty of apps and sites that use AIS technology so you may view other vessels that have AIS, however they cannot view you. Another form of AIS technology that can be found is personal wearable AIS beacons attached to life jackets for man-overboard safety. These AIS beacons are battery operated and low power devices, small enough to fit in your palm. They have limited range, due to a short antenna and the possibility of being blocked by waves, but the person overboard can be electronically visible to any AIS-equipped boat within in about 4 miles.
AIS became mandatory on many commercial cargo and passenger vessels years ago, after enhancing security due to 9/11. In the last couple of years, AIS has become more popular and expanded to include mandatory systems on more commercial vessels 65 feet and larger.
Safety is one of the biggest benefits of AIS, whether you are a large ship, or just a recreational boater out for the weekend.
Knowing the exact heading of another vessel that feels a little too close to comfort, may ease your mind. You will be able to know if there is assistance nearby, in case something goes wrong out on the water.
If you are traveling in a group with other boats and the weather gets bad or foggy, AIS can help you keep track of each other electronically. Weather will not affect AIS, so if you are a long-distance cruiser traveling at night or in the fog, especially in the shipping lanes or congested harbors, AIS is a no-brainer. And whether you go with a Class B AIS unit or not, there is an AIS option for every boater to provide more safety on the water.