We’re producing a new version of our AIS AtoN that has an integrated receiver. Most installed AIS AtoNs are transmit only. They don’t do a whole lot—send
out Message 21, which gives a position report and the status
of the light on the buoy and a few other things. It tells you
where that buoy is via AIS and is displayed on your chart
One of the areas we’re looking at is sending weather data
over AIS from AtoNs. It gives weather data right at the buoy,
which may be very different from the conditions being experienced at the weather station or dock. There is a question of
whether that data should be transmitted directly so all of the
vessels near the buoy can see it or is sent back to NOAA
(National Oceanic and Atmospheric Administration) or the
Coast Guard for vetting and then retransmitted.
Another opportunity is the inland waterway system. There
are hundreds of locks throughout the river system, which are
ideal locations for AIS AtoNs. The Corps of Engineers is experimenting with sending waterway current information via virtual AIS AtoNs that would be “located” in advance of a lock.
The Alaska Marine Exchange has tried for years to get
weather stations over AIS deployed, but there are political hurdles. They currently have 110 AIS monitoring sites that could
incorporate weather information. The Exchange also wants
DSC deployed on these. We’re working with them and hope
to have experimental sites up and running this spring or summer.
Broadcasting ship’s weather is another application. The
Washington State Ferry System is looking at putting experimental AtoNs with weather stations aboard some vessels to
report weather data.
The US has relatively few AIS AtoNs compared to other
countries, due in part to budget constraints. In fact, some
interests are pushing to remove physical AtoNs and replace
them with “virtual” or “synthetic” AtoNs, which are transmitted by AIS base stations. That’s short sighted because AIS
buoys can be smaller, requiring smaller lights and batteries.
Also, AIS buoys are still real buoys and can transmit real
weather data and be seen by small boats that may not have
AIS reception and chartplotter electronics.
New uses for AIS AtoNs
In late 2008, IALA (International Association of Lighthouse Authorities) approved a recommendation that an AIS transponder could
provide substantial benefits as an aid to navigation. Since then
manufacturers have taken the initiative to develop AIS AtoN technology. One of them is Shine Micro of Port Ludlow, WA. We asked
company owners Mark and Judy Johnson what they’re working on.
Here’s what they said:
would be delayed, making room for the Class A units. Class A systems
transmit their information in 26 milliseconds approximately every 2
seconds, while Class B units transmit every 30 seconds in order to take
up fewer time slots. If a port area’s transmissions start reaching a high
load, certain types of vessels or vessels in a particular area can have
their transmissions redirected or delayed by land-based vessel and
harbor monitoring authorities, taking advantage of another safety net.
In recent years, AIS has notched up its contributions to vessel
safety as a virtual AtoN (Aid to Navigation). A couple of years ago,
New Zealand AIS manufacturer Vesper Marine harnessed the technology to create a virtual buoy to mark a dangerous submerged rock just
inside the entrance to a remote cove visited by cruise ships. Company
co-founder Jeff Robbins says the rock is noted on charts but that several attempts to mark it with a buoy were unsuccessful due to heavy
sea conditions. The solution was to build a solar-powered AIS transmission tower (accessible only by helicopter) on a nearby cliff peak.
Signals from the tower paint a virtual buoy on the plotter, ECDIS or
other AIS-enabled display that is within range, identifying the submerged rock. Setting up and maintaining this system has proven to be
cost effective compared to the expense of placing, maintaining, repairing and replacing a physical buoy.
An interesting application demonstrated by Vesper Marine was its
use of AIS at the America’s Cup races last fall in San Francisco Bay to
establish a virtual perimeter to keep spectator boats off the course. The
virtual boundaries were visible on chartplotters aboard AIS-equipped
In still another use, the technology was tested on the Mississippi
River where power lines cross over the river. Tall cruise ships navigating the river run the risk of contacting the sagging center of the lines
at times of high water. Sensors were set up to transmit water flow and
water height to nearby AIS beacon towers, which was forwarded to
cruise ships, giving the location and height above water of the slow
Application-specific messages such as weather, currents and navigation issues can be broadcast throughout the AIS system, as well.
One AIS manufacturer that is developing technology for weather and
inland waterway applications is Shine Micro of Port Ludlow, WA . The
company is also involved in a project with ocean data services
provider Liquid Robotics to deploy surfboard-size platforms called
“wave gliders” that transmit data about sea conditions and water quality, among other information. Set up with solar panels, sensors, instruments, satellite interfaces and AIS receivers, the autonomous wave-powered devices can go for months unattended.
Shine Micro’s Mark Johnson says, “A lot of them are employed in
the oil and gas industry. There are so many out there now in some
areas that they’re getting hit by ships. We think the solution is for them
to transmit AIS data to nearby vessels.” ME
About the author
Glenn Hayes is a freelance photographer and writer based in west central
Florida. His marine and boating industry experience extends back almost
three decades. A second-generation professional photographer and journalist, he specializes in marine commercial, editorial and fine art photography
and writes about all aspects of the marine and travel industries. He can be
reached at www.HayesStudios.com.
to pose a collision hazard would be listed first, with the furthest away
temporarily dropping off the list.
Class A transmitters also take priority over Class B units. If a situation
were to occur where transmission slots fill up, the Class B transmissions