AIS is a new collision avoidance and ship identification system, and I have been surprised to find in my conversations with boaters that very few people actually know about it. AIS stands for Au tomatic Identification System and, in a nutshell, what it does is allows you to find other vessels in your vicinity equipped with AIS—and to know their position, course, speed, name, and much more.
There are two parts to an AIS system, a transponder and a receiver. As you would guess, a transponder sends out the data and a receiver accepts it. Large commercial vessels are now required by international law to carry and operate AIS systems. Transponders currently available are designed for those kinds of vessels and are prohibitively expensive for the average yacht owner. But receivers are rather cheap and interface directly with newer electronic navigation systems.
Once installed you will be able to see on your laptop or chart plotter other AIS equipped vessels right on your screen, and find out a wealth of information about them. This is a big step forward for collision avoidance at sea, far easier to use than radar and with much more data. Without contacting the other vessel on radio, you will be able to see their name and the kind of vessel, and with speed, position and course, you can easily determine if you are on a collision course.
Of course, since not all vessels are AIS-equipped, including other yachts and fishing boats, AIS does not yet replace radar and it certainly does not replace your eyes. But in the future I think it’s going to become part of the standard navigation arsenal on yachts.
Next month: more about AIS, including what’s available and what is coming soon, including less expensive transponders designed for small vessels.
Russell Easby-Smith left his Chesapeake Bay home base last year to live aboard and sail Paulina, currently from Grenada. He welcomes questions on all things technical on boats, care of: editor@allatsea.net.
