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AIS information sources Resources Panbo Ben goes into much greater detail on all forms of electronics than anyone else I know. He is a big proponent of AIS. Read his section on AIS
USCG Navcen Here you will have your questions answered about what is AIS, how it works, how its broadcasts, and types of AIS.
Explains MMSI numbers
Fred Pot runs UAIS and here you can get information on AIS. Get copy of AIS conference for ship operators in Seattle Nov 2002.
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Automatic Identification System AIS
One of the fastest and biggest growth areas in marine navigation is AIS. Having an automatic identification system AIS transponder unit onboard, will turn your boat into a radio beacon continuously transmitting speed and course. Conversely having an AIS receiver allows you to track a ships COG, SOG. This can be very important information for navigating in shipping lanes and channels.
quick links
what is AIS, what equipment do you need, Class A AIS, Class B AIS, Class B AIS transponders, Software, Other sources of AIS discussion, Other Collision avoidance devices
How does AIS work?
AIS transponders have been a legal requirement on ships over 300GT for a while. Yachts with AIS receivers can see those vessels on a radar type plot.
There
are two types of AIS transponders class A & class
B. Class A AIS transponders are for Commercial
shipping, and transmits via 2 channels and typically is fully integrated
into the ships navigation systems. Class B transponders are for smaller vessels.
Having discussed AIS with maritime industry workers including ship Captains and Pilots, I can tell you they really like the system. So does Panbo's Ben Ellison and many others in the marine Industry. My discussions with the Pilots concluded that while they like the system and believe it should be on many recreational vessels, they worry about too many signals in crowded channels. They would have to deal with lots of targets on their plotters which could be confusing.
The Biggest Benefit for having AIS is for you to be able to figure out if you are on a potential collision course (CPA) see above diagram. So the suggestion is for recreational vessels to have the receiver only. Since Blass B transponders are still not approved in the US (April 2007 and still no approval) its a moot point.
The Difference between Class A and Class B is the transmission rates. Class A broadcasts every 2 seconds, while Class B is only very 30 seconds. This means for fast moving craft like high speed ferries you will get a ping twice a minute. At 20 knots the high speed ferry has moved quite a distance.
For Merchant traffic to see you on radar you need a reflector. Radar does not give you the same information that AIS does, also it is harder to read, while the AIS signal gives you precise information on the approaching vessel.
Navigation Software developer Nobletec's diagram below shows the AIS setup using the AIS 100 engine, the same setup would be appropriate for any AIS engine. You need a VHF aerial, a GPS, software and display. If you already have the VHF and GPS and a plotter, then adding the AIS unit could cost as little as $200. The AIS engine will send NMEA information to any AIS capable receiver.
The same hardware setup would be used for a chartplotter depending on whether you use chart cartridges for a plotter or software with a PC.
The
stand alone unit costs about $350. Much cheaper than radar.
Uses
your existing GPS and VHF aerial.
There are discussions on VHF aerials which hinge on whether to have a separate aerial for AIS or to use your existing VHF aerial. Many find it is just as effective to use a splitter on the existing aerial., and just as cheap. Splitters are not cheap.
MMSI Number
If you elect to get a class B transponder you will need to program the unit with certain information including your MMSI number. If you have not already got one You will need to apply for a MMSI number the same as for DSC.
Some of the details you will need to get programmed into the transponder include; Ship's name (20 characters maximum), Vessel's radio call sign (7 characters maximum), MMSI number, Vessel type and certain vessel's dimensions. This information is sent in your AIS signal which tells the receiver who you are COG, SOG, call sign etc. United States Coast Guard on Class B approval October 2008
Now to the manufacturers producing AIS units
This just one example from Simrad
Connected to radar or an electronic chart system, the AI80 provides a detailed overview of the shipping in your area. The vessel's primary GPS receiver needs to be interfaced with the AIS and is used as the main positioning source. However, the AI80 also incorporates an "all-inview" GPS receiver, which can be used as back up for the primary GPS receiver. The cost for this class A is in the $4,000 region.
SI-TEX-NASA
Other suppliers of AIS receivers include;
Simrad's new AIS class B, the A150 retails for £800 or $1,600. The first color AIS class B unit. This unit receives and transmits data (not in the USA) but is good in Europe. The daylight viewable color screen and easy interface with built in coastal maps make for simple watch keeping. Range rings allow for setting of alarms to warn of incoming traffic. The unit connects through NMEA 200 based SimNet marine network. For DSC capability connect to a SimNet equipped DSC radio and call via the MMSI number of the selected boat. Buddy tracking allows you to track 3 friends.
Standard
Horizon Chartplotters
The CPV350 is capable of displaying AIS signals (when optional AIS receiver connected) as Targets on the chart page in relation to your position. In addition the CPV350 can be setup to alarm when a target ship is within a specific time or range zone, to alert you to avoid a collision.
Raymarine,
Inc. announced at th
Note; Most class B transponder units are awaiting FCC approval. Comar below is one of the first to get class B certification in Europe.
There is still no FCC approval for transponders in the US. 10/12/07
update 7/1/08
Shine Micro may have a short term answer to the FCC
We have been waiting in the US for the FCC to allow Class B AIS units for some time. At present we can purchase receive only AIS units. This is still a good option as the AIS receive only units allow you to pick up any ships AIS broadcast in you area. The AIS broadcast will give you the ships COG and SOG which can be plotted on your chartplotter. Simple observation of the chartplotter gives you a handle on ships movement in your area. When Class B is allowed you can broadcast your AIS signal. Shine Micro has come up with a solution for those waiting for Class B
approval. By the RadarPlus now for $799 and when Class B is approved you can
get it activated for an additional $200. Shine Micro's Description RadarPlus AIS-BX Class B AIS in Receive-Only Mode $799.00 USD Class B AIS is a low cost safety of navigation aid. With the RADARPLUS®
AIS-BX you can transmit vital data about your vessel while viewing the AIS
transmissions of others in real-time. In addition, Shine Micro is an FCC
approved issuer of the Maritime Mobile Service Identification number
required for identifying your vessel, and provides this unique ID number
free with your purchase. The assignment of your MMSI, or registration of an
existing one, is online*; making activation easy. Transmit Your Position
Operating an AIS-BX ensures you are seen by other AIS fitted vessels,
including the U.S. Coast Guard, Search and Rescue Operations and most
commercial ships. Safety Related Message If configured accordingly, the
Safety Related Message button allows the user to transmit a distress alert
quickly and easily to all vessels and base stations within range. By default
the AIS-BX is programmed to engage "Silent Mode" when the "S" button is
pressed. Note: The SRM feature is in addition to the international AIS
specification and may not be monitored by all reception equipment. This
feature does not replace use of normal VHF emergency procedures. Internal
GPS The AIS-BX includes an integral 16 channel GPS. Standard NMEA Interface
The AIS-BX can interface with any NMEA compatible GPS plotter or suitably
configured PC. Water Resistance An IP65 rated aluminum case ensures that the
AIS-BX is able to operate in harsh environments. Online Activation* *Assign
or register your MMSI number and activate your transponder online at
www.shinemicro.com, or contact us to receive the forms via email or fax.
Comar's new CSB200 Class B AIS. Connected to a compatible on board PC running a Navigation Program, or Chart Plotter, information received from other vessels or shore stations can also be displayed on screen giving the skipper or navigator a visual interpretation of the name, position, course and speed of vessels within VHF range. This information is updated every 3 seconds to 6 minutes depending on speed and rate of turn, enabling the track of the vessels in range to be plotted. Cost about $1,200. The receiver switches channels every minute. Comar has a single frequency AIS listener SLR100 for approx $540.
ACR
The
see through casing is interesting and I guess it allows the lights to be
seen without compromising water tightness. Looks cool though.
AIS
on your PDA that's cool, it You will need an AIS receiver plus GPS and an aerial.
See list of compatible hardware.
If you already have software check your manufacturer to see if they have AIS compatibility. I would think there is an upgrade.
Subscription required but highly recommended.
Each
month many topics are covered and the February 2007 edition has a test of
the NASA engine. They say it works as advertised but they would like to
see improvements in some of the keys.
Terry
Sargent has many articles on his site including a detailed account of his
use of AIS. Very Interesting reading from a user. He discusses AIS
engine, software, antennas and antenna location. Plus some interesting
experiences.
Other Collision Avoiding Products
MARPA is an acronym for Mini Automatic radar Plotting. If you have a suitably equipped Radar you place the cursor over the target and then tell the system to acquire the target. The radar will analyze the data and reproduce the target as a track on the screen showing COG, SOG and CPA.
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You
could also use a stand alone AIS unit like the NASA (Si-Tex in the US) one
here. The screen will show you the targets in your VHF range.
dual channel AIS receiver plus 16 channel GPS. GPS and AIS revivers are
built into a 51" tall fiberglass aerial. COG and SOG are updated
every 10 seconds. Look at SeaCas list of compatible software and hardware,
which is a list of who's who in the industry. Cost approx, $1,300.
are now AIS compatible. Previous models can be
upgraded.
cost in the $1,000 region once approval has been
passed. 
will work on your PC also like other
navigation software.
