AS K N I G EL BY NIGEL BARRON
The Inside Track NIGEL BARRON recommends an electronics upgrade that would benefit most Puget Sound boaters this winter: An AIS tracking system. Winter projects are in full swing here as we greet the New Year, and fittingly, I talked with a friend of mine about upgrading the electronics on his boat. He has an older Raymarine system and needs to put together a new system for his vessel. We’ve discussed electronics here before, but the key parts are the transducers (wind, speed, depth), the MFDs (multi-function displays), and other ancillary sensors, such as radar, VHF, and AIS. He asked me what I thought about AIS, which stands for Automatic Identification System, and if it made sense for him to add this to his boat. The short answer is: yes. More and more, and particularly in Puget Sound, I would take AIS over radar. If you’re not going out in the dark or the fog, you get much more useful information from AIS than radar. It shows up right on the chart plotter. In our own B&G system, I can move the cursor over a target and get the name, speed, direction, and often the destination of the vessel, all the while seeing on the display where the boat is relative to us. Of particular use when sailing around Puget Sound is the CPA (closest point of approach) and TCPA (time to closest point of approach). I love this function because it shows me in almost real time what course changes or speed changes do to my position relative to the other vessel. Starting with the basics, AIS is a tracking system that uses transceivers (transmit and receive) to share a boat’s unique information over the air. The vessel’s name, position, speed, and heading are just some of the bits of information that are transmitted. As you can imagine, it’s proven to be an invaluable tool for collision avoidance, search and rescue, and tracking. Shared via the VHF antenna, the information is received by other AIS units and then displayed on board your vessel. There are a lot of different models and brands to choose from when shopping for an AIS, but the reality is that they all perform the same basic functions. When adding AIS as part of a new electronics package, most people tend to stick with the brand that matches those electronics. There 68
is some variety in price, but they are all around $1,000. If one seems a lot cheaper than another, it might require you to buy a separate VHF antenna splitter or it might have a different transmit power. All AIS that are going to transmit information will need the antenna splitter (which might be built in) and a GPS antenna. Some will have the GPS built into the unit, but it’s really only going to be in a rare situation that you wouldn’t have an external GPS antenna dedicated to the AIS. In terms of how and when to use it depends on how much you want to adjust alarms and settings. For the most part, AIS is something that’s just going to run in the background, and you’ll start noticing little triangular targets on your chart plotter. The CPA information discussed earlier is the most common alarm that you’ll want to adjust. If you have an alarm set for 1 mile, which seems pretty close when the other boat is a 600-foot freighter, that alarm is going to go off a lot in your marina. Most units also allow you to toggle between transmit and silent. If you race your boat, silent allows you to not send real time information related to speed and heading to all the boats around you. In both instances, remember where you left the settings and adjust accordingly. One last nice thing about AIS is that a lot of websites and apps will take the information transmitted and display it on a web-based map. One example of this is marinetraffic.com. It’s fun to see all the ships out there and the routes that they take as part of global trade, even if you are in an armchair. Nigel Barron was born in England and developed his sea legs at an early age. He is currently the project manager at CSR Marine in Seattle, where he has worked for 15 years, first as a rigger, then an installer, and now in his current role. He is also the captain of Zvi, a Reichel-Pugh designed and McConaghy-built custom race boat from Seattle.
