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AIS Information Overload

Too Much of a Good Thing

As the number of AIS targets on plotter screens continues to grow, when does the clutter overshadow the communication benefit?

Crossing the Gulf Stream en route to the Abacos last summer helped me fully appreciate the value of basic AIS. Our course ran athwart the paths of nearly a dozen cruise ships, coming and going. The AIS returns delivered to the chart plotter by our Matrix radio, the innovative VHF-AIS combo unit from Standard Horizon (, reassured us that these brightly lighted behemoths weren’t as close as they seemed to the naked eye. Knowing the closest ship’s name was particularly useful, allowing us to hail Carnival Whatever just to see whether the bridge crew had noticed us on radar.

Vesper Marine makes AIS units that offer simple functionality for intrepid boaters.

That Bahamas passage would have convinced any skeptic that an AIS receiver represents money well spent, but along the way we noticed something else—quite a few recreational vessels with Class B AIS transceivers, some of them less than 30 feet long. Class B is the designation for recreational-vessel AIS, and having a transceiver, as opposed to my simple AIS receiver, means that your vessel is broadcasting her name, position, heading, speed, and so on, as well as receiving data from other AIS boats. AIS transceivers are catching on fast.

What happens if adoption of Class B AIS transceivers becomes as widespread as GPS? Recreational AIS broadcasters in our more popular harbors and waterways may well create a great deal of clutter on our plotter screens as dozens, even hundreds of triangular symbols compete for our attention, not to mention the various close-approach audible and visual alarms. There is a historical precedent for this. Before the days of cell phones, vessels hailing on VHF Channel 16 could produce such a maddening cacophony that many boaters in crowded waterways preferred to shut off their radios, myself included.

Vesper founder Jeff Robbins

A ‘Star’ to Steer By

Vesper, meaning evening prayer, derives from Hesperus, the Greek name for the “evening star” we now call Venus. Vesper founder Jeff Robbins notes that Venus is one of the four “navigational planets” that mariners traditionally steered by. Robbins spent his entire professional life developing software programs, then the hardware to run them on. At one point, he and his wife ran away to sea, and spent seven years cruising the Pacific and Caribbean aboard their Nordic 40 sailboat, named Vesper. Even underway, the inventions kept coming. “I kept myself challenged by doing ‘mad science projects,’ developing a variety of hardware and software gizmos for our own (and sometimes friends’) use onboard,” he says. “I was always interested in doing something to help avoid collisions, particularly for short-handed folks or couples cruising.” Thus Vesper was born and began bringing collision-avoidance products to market. “Our technology will certainly help make sense of a crowded waterway and is incredibly useful when our eyes are fooled,” Robbins says. “As you know, it can be quite difficult to assess a complex situation simultaneously involving dozens of vessels.”

Would the popularity of AIS actually diminish its value as collision-avoidance technology? That question became the basis of conversations with Jeff Robbins, an AIS innovator and cofounder of Vesper Marine (, and others in the AIS business.

Founded in 2007, Vesper Marine has been winning technology awards for its target-filtering technology ever since, including the 2012 National Marine Manufacturers Association Innovation Award for its WatchMate Vision, the world’s first dedicated Class B AIS transceiver with touchscreen control and built-in Wi-Fi. Vesper’s genius was to combine software algorithms and user settings to display only those AIS targets that might pose a threat and to activate alarms sparingly (and thus less annoyingly).

Robbins, himself a bluewater cruiser, agrees that Class B AIS will eventually find its way onto a much higher percentage of recreational boats, particularly cruising vessels, and when it does there will be a real possibility for overkill. He says he’s surprised that the adoption rate hasn’t increased faster.

“Of course the difference between GPS and AIS is the clutter [AIS] can create on displays; false alarms that will drive you crazy; and the need for effective filtering,” he says. “I hear numerous stories about recreational boaters shutting off their AIS systems when they come into crowded waterways, but of course that’s probably the most important time to have it switched on. You are more likely to have a collision at that time.”

Robbins says he and his engineers are working to devise even better filtering solutions. “I know that the time is coming when it will be very important that you must have the ability to reduce the clutter and get the alarms under control,” he says. “Others, if they have done anything at all, have taken different approaches. Some are even doing things like ‘filter out all Class Bs.’ That might be like saying I only care if I hit something really big. Instead our approach is not to filter based on the type of vessel or how big it is; rather we choose our visibility and alarms based on the actions each vessel takes. We now have many years of customer experience and feedback with our technology on a wide variety of boats and conditions and this is something we are very fortunate to have.”

Boat Beacon from Electric Pocket (, a British company, is another innovative AIS product. Like WatchMate, it was developed by a cruiser for other cruisers. Boat Beacon is a $10 smartphone app that uses coastal cellular networks to broadcast AIS information on the network of shore stations collecting and sharing AIS data.

Boat Beacon screenshot

Boat Beacon is a smartphone app that offers AIS function by connecting to the Internet through cellular networks.

Electric Pocket CEO Steve Bennett says he is not a big fan of AIS transceivers for recreational vessels. Receivers, yes. He says the main purpose of AIS for pleasure boats is so that they can detect and avoid ships, not the other way around. “Class B VHF AIS Transmitters, which are recommended for recreational users, are very low power.... This tends to reduce how much they can clutter the AIS seascape, but also really limits their usefulness in alerting other boats to your position,” Bennett says. “You should not expect or rely on other large boats seeing you or being able to change course in time to avoid you. In my opinion a class B transceiver is not a worthwhile investment.”

Bennett touts the fact that vessels with Boat Beacon will not show up on conventional VHF AIS Systems. Boat Beacon boats “transmitting” their position will only be visible to other boaters who have Boat Beacon or an Internet-based AIS system such as Marine Traffic (if they have a valid AIS identity, an MMSI number). 

“Boat Beacon will not add to the VHF-AIS recreational ‘clutter,’” he says. “The main purpose of the transmit feature in Boat Beacon is so that friends and family or other members of your flotilla can track you. It is not for collision avoidance. The receive and CPA functions of Boat Beacon provide the collision-avoidance safety features.”

Where AIS solutions and the related technology take us in the future is anyone’s guess. But we can all agree that the improved situational awareness and communication available even today has been a long time in coming.

This article originally appeared in the March 2013 issue of Power & Motoryacht magazine.