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Vesper Marine’s Virtual Buoy System

Zone Defense

Vesper Marine marks a no-anchoring area, using AIS to place virtual buoys and improve communication via an automated system.

The author, left, and Jeff Robbins, CEO and cofounder of Vesper Marine, discuss virtual buoys and addressed safety messages. The Vesper WatchMate Vision has a touchscreen and built-in Wi-Fi (right).

Jason Y. Wood and Jeff Robbins

Join me, if you will, for a glimpse of boating in the future. It’s a world where your boat tells you just where to go, and what to do while you’re there. In a manner of speaking, your helm will be equipped with a heads-up display, like the visor on the helmet of an attack-helicopter pilot. All that tiny type that we now see on paper charts next to aids to navigation, or shared via cursor-hover on electronic charts, will be transmitted by the helm onto that display, floating next to the navaid in question. Hopefully the helmet won’t be too heavy by then. How are your neck muscles?

I’m joking of course, but I did just return from a sea trial on Long Island Sound, where Vesper Marine (, the New Zealand-based company focused on AIS solutions, is working with the New York Power Authority to mark a no-anchor zone with some advanced “virtual buoys” that appear on an AIS-enabled chart plotter—and only there.

The power company has four subsea cables crossing beneath Long Island Sound from the north side of the sound in New Rochelle, New York, to the south side, on Long Island, in East Garden City. The four 345,000-volt, self-contained, fluid-filled cables carry 600 megawatts each, and are jetted into the mud at the bottom of the sound, so they’re relatively protected. But anchor strikes from ships and barges can cause problems. The last time a cable was struck was in January 2014, when it was hit by a barge anchor. “Dielectric fluid runs inside the conductor, so if you breach the outer sheathing, you could potentially have dielectric fluid that leaks into Long Island Sound,” says Bob Schwab, director of asset maintenance management for the New York Power Authority. “In that case it probably ended up releasing 6,600 gallons of dielectric fluid. Even though we took the cable out of service, we have to keep the fluid pressure and flow to keep the salt water from going inside the cable.” On top of that environmental impact, there’s the power outage, which can have significant economic and public-safety repercussions. And also the cost of the whole mess, which ran to $34 million from the capping of the cable to repairing it in January and February, during what ended up being a very cold winter.

Rather than stringing buoys all over a full-width section of Long Island Sound—which would create a hazard of sorts in their own right—the powers that be looked for a better solution. “I actually talked to a couple different companies, and I spoke to a company that used a system that ended up following vessel traffic through the Automatic Identification System, where each vessel over a certain tonnage has to transfer information about the ship heading, speed, the name of the ship, and the MMSI number,” Schwab says. “And we can also look back at the history and collect course information.” 

It sounded like a pretty great idea. Except Schwab thought it could be better. “That company said they would work with the system provided to develop protection zones and different rule sets, so if a vessel came into the area and it looked like the potential was there for them to anchor, they would get an alert—hey, this vessel is about to anchor,” he says. “But in their system that’s where it stops. They would get the alert and then they would have to notify the Coast Guard. And the Coast Guard would have to notify the ship and tell them not to anchor.”

“The problem with this is, first of all, you’ve got to have someone manning the system 24-7,” Schwab says. “And there’s a lag time before the ship gets notified not to drop the anchor.”

Vesper began to develop a solution, using both software and hardware, that would put the two-way power of the AIS system to work, both through virtual buoys that exist on the system all the time, and through another system that reads vessel movement and responds to it accordingly.

Virtual buoy system

Image: Rose Point Navigation Systems (

This navigation chart is part of the desktop software that the New York Power Authority uses to monitor its new Vesper Marine AIS safety warning system, which protects subsea power cables from anchor strikes.

“A system of virtual buoys is created by a beacon on shore on the north side and one on the south side, so there’s overlapping coverage,” says Jeff Robbins, CEO and cofounder of Vesper Marine. “The overlapping coverage provides virtual markers on the chart, just as if they were buoys in the water, but you just can’t see them [on the surface] marking the cable area. So when [AIS-equipped] vessels come by, they know right where it is.”

But the data is not merely a one-way street. Instead of just being a speed-limit sign on a roadway, it’s more like one of those radar devices that police set out on the side of the road to tell you how fast you’re going. The Vesper system is similar, but has a much more involved task. It doesn’t just tell boats about the area they’re in, it finds out what the boats are doing. “We monitor the traffic and send the data to the Internet, where servers analyze the data constantly,” Robbins says. “The software is looking for behaviors: Does the vessel slow down or turn upwind? Or does it go very fast and slow down rapidly? With that kind of ‘pre-anchoring’ behavior, the system looks at the vessels closely and does two things: It sends an alert to the New York Power Authority’s operation center. It appears on Bob Schwab’s screen with an alert message, and it can also send e-mails and text alerts and so on. It records all of this information as well, so the NYPA has a history of any event that ever occurred and all the vessel movements, so it can go back in time and replay those. But at the same time it sends the vessel a message to alert the captain that he’s potentially anchoring in a dangerous location.”

The NYPA system transmits an addressed safety related message, a somewhat underutilized function of the AIS system. This means that the message is addressed specifically to that particular vessel and will only show up on that vessel and not any others. And this is understood and handled by all Class A and Class B transponders, as it’s a required part of their specifications.

Now here’s where the AIS system’s strengths really come into play. Because AIS by definition shares extensive data on the vessel in question (keeping in mind that most boats using AIS are commercial vessels required to carry it by regulation), the NYPA and Vesper Marine can tailor the alert system to the needs at hand.

For example, only vessels of a certain size, say, commercial ships and barges, will carry ground tackle large enough to pose a risk to the cables buried in the muck. Because of that, most recreational boats will see the virtual buoys (good for reckoning just exactly where they are), but won’t get pinged with the warning messages should they stop to dunk for flounder. “Once we get that data, we can analyze the data and send them a message very fast,” Schwab says. “With the vessel traveling about 8 knots across our cable area, it only takes about five minutes for it to cross, so you can see if they’re about five minutes away and they start to reduce speed, you have to notify them right away. You can’t rely on contacting someone else and hoping to get in touch with them.” 

And because the NYPA transceiver is well situated, the range that Schwab gets from the system is very helpful. “We’ve developed a number of protection zones around the cable system, and we have two installations of the hardware to transmit and receive the information: One is located on the Long Island side and the other is in our home office in a White Plains office building, which is on the 18th floor and gives us very good range,” he says. “Because we’re so high up, I can actually monitor vessel traffic in the Hudson River, Long Island Sound, and the Atlantic very close to Manhattan.” At this writing the protection zones were due to go to fully automated mode in a matter of days.

“It’s a Web-based system, so even if I’m on vacation I can go on my cell phone to see what’s going on,” Schwab says. “If I get a message or even make some changes to the protection zones for vessels—there are a lot of attributes that can be changed.” Schwab outlined one instance where a construction project at a nearby marina meant barges would be moving through the protection zone and making movements that would draw the warning messages on their required AIS systems. “We have a lot of traffic here at one of the marinas where they’re working,” he says. “I don’t want to keep sending the messages that they’re getting close to the cable every day, so I can put them on an exception list.” Schwab also outlined a case where a work zone to repair the cable could add recreational boats to a protection zone delineated by the system, only for the time when the workboats are in position. The recreational boats using AIS would have the benefit of greater understanding of what’s going on without getting too close.

During the test period when the system was coming on line, Schwab said one of his first customers was a U.S. Coast Guard vessel. “They came into the cable guard zone and slowed down, and the system sent them a message,” he says. “Then they turned and slowed again, and they got another message.”

The Coast Guard is mostly concerned with safety at sea, of course, rather than the power system remaining online. But a system that’s clearly equipped to do both, and much more, is definitely worth slowing down for, to have a closer look. And maybe boaters considering AIS should do the same.

Check out a video about Vesper Marine’s virtual buoy system here. ▶

This article originally appeared in the September 2016 issue of Power & Motoryacht magazine.