This is an introduction to the marine AIS (Automatic Identification System), its technology and user devices that take advantage of the system. You may find this useful if you are a skipper of an ocean going vessel, are working in highly congested waterways or journalist/researcher needing to understand AIS in more depth.

1. What is AIS?
An introduction for workboat
and pleasure craft owners

2. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
What is AIS? - Automatic Identification System
Slide 2
The Basics…
AIS is an international ship identification
standard that allows vessels to transmit
and receive information about vessels
in the immediate vicinity
• Your boats unique identification
information
(Maritime Mobile Service Identity)
• GPS data to record & track your
position
• VHF radio signals for receiving and
sending AIS information
This is assembled in an electronics enclosure, sometimes
with its own display
To Work AIS Needs;

3. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
What is AIS? - Automatic Identification System
Slide 3
The Basics, who uses AIS and what information is sent…
• All international commercial boats over 300 ton must use AIS Class A
• Private boats under 300 ton are able to use AIS Class B
• Other vessels as determined by local authorities must also use AIS
(Commercial and Pleasure)
AIS data transmits over two dedicated digital marine VHF channels.
The data is sent from each vessel every few seconds and contains;
For AIS Class A
• The vessel's Maritime Mobile Service Identity (MMSI)
• Navigation status – "at anchor", etc.
• Rate of Turn , Speed over Ground, Position, Course over Ground,
True Heading, Time Stamp
Sent every 2 to 10 seconds depending on a vessel's speed while
underway, and every 3 minutes while a vessel is at anchor. Static ID
data, such as vessel name, are broadcast every 6 minutes
For AIS Class B
• Maritime Mobile Service Identity (MMSI)
• Speed over Ground, Course over Ground, Position, True Heading,
Time Stamp
Sent every 3 minutes where speed over ground (SOG) is less than 2
knots, or every 30 seconds for greater speeds. Static ID data, such as
vessel name, are broadcast every 6 minutes
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4. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
Why is There a need for AIS?
Slide 4
The main reason!
The Ship Captain’s View
The Small Boat View
The View Nobody Wants!

5. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
For pleasure craft and light commercial vessels...
• Crew safety – allows others to see where you are
• Improved ship to ship communication
• Provides you with situational awareness relative to other vessels
• Boat investment protection
For search and rescue…
• Allows both marine and air rescue craft to identify your location
Other uses…
• Commercial fleet tracking
• Virtual and Synthetic Aids to Navigation
Why is There a Need for AIS?
Slide 5
And more than just collision avoidance…

6. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
Class B AIS systems are becoming such an important
addition to smaller vessels for its safety benefits
• There is a growing understanding of the improved safety that AIS offers;
• Providing collisions avoidance alarms
• Being able to signal your location to search and rescue
• Transponders offer a back up GPS
• Being able to be seen and see other vessels (ship to ship coms by name)
• An increased number of reported near misses. When someone first starts using AIS
they soon become aware of how luck played a big part in past voyages as they
suddenly gain visibility of how many other ships they come in close, but often
invisible, contact with.
• Increased peace-of-mind, particularly for shorthanded crews where an extra “pair
of eyes” is greatly appreciated.
• It’s fun to see what other vessels are “out there” and where they are going.
Class B is not mandated, why is its use growing?
Slide 6

7. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
How does VHF carry AIS
information
AIS Technology, Introduction to How AIS Works
Slide 7
AIS Receiving
Shore Station
Ship A
Ships broadcast short digital messages giving
details of their identity, position, course and speed.
Any other vessel within a radius of 37km/20nm or so
can receive that information and display it.
Each AIS transmission from a ship only takes
milliseconds, so even though each ship can be
updating its AIS information every few seconds,
there is a plenty of VHF capacity for many
hundreds of ships to exchange information at one
time within the 37km/20nm radius.
Each time slot
represents 26.7
milliseconds
The AIS info for Ship A sends the
position message in one VHF data
time slot. At the same time it
reserves another time slot for the
next position message.
The same procedure is
repeated by all other
AIS-equipped ships

8. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
AIS Technology, How it Works
Slide 8
Where does radar fit in
Radar definitely has its advantages and for large
motor powered vessels it is likely to be essential in
many circumstances. However the introduction of
AIS gives you a “virtual neon sign” on your boat
that all large commercial vessels and many smaller
vessels will see from miles away.
AIS also has the following advantages over radar:
• Small vessels wont be visible in big swells by
radar
• More chance of being seen when traveling
close to land or behind islands with AIS
• Can see AIS enabled AtoN’s (Aids to
Navigation)
• AIS is Less affected by weather conditions
• AIS is low power consumption
• AIS offers good value for money as it is lower
cost than radar
• Receive Hydro and Meto data from AIS
equipped buoys
It’s worth noting that some multi function displays
allow you to overlay AIS information on radar
screens. No technology is100% foolproof, but both AIS and Radar are
highly valuable safety features and complement one another.

9. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
Class B AIS products
• Black boxes
• Displays
• Chart plotters with AIS
Class A AIS product examples
What Type of AIS Products are Out There?
Slide 9

10. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
Chart Plotter/AIS Black Box… Versus Standalone AIS
Slide 10
• A dedicated AIS display provides all AIS information at a single glance without
having to drill down through complicated menus in times of stress
• AIS and chart data can get very cluttered in high traffic areas, making individual
vessel information hard to identify
• The scale for a chart versus the scale needed for useful AIS viewing is often
different meaning you will be continually zooming in and out on a plotter to get
perspective
• Some AIS chart plotter software is limited and will only tell you there is a "Dangerous
Target". Not enough information to make a decision on in low visibility, high stress
situations
• Some AIS displays like the WatchMate provide the ability to filter non important, low
risk vessels focusing your attention on the most important targets only
• Standalone AIS PC software and chart plotters don't have sophisticated Alarms
settings or Multiple Profiles that make using AIS information easy
• Being a safety device its always reassuring to know that you have one piece of
equipment with the sole purpose of continuously monitoring hazardous situations
• Installation is simple with a dedicated AIS device, no complicated interfacing,
settings and menu navigation issues to deal with
• If you are concerned about power, standalone displays use very little power (only
3W in the WatchMate’s case) and can often be left on permanently
The benefits of a dedicated AIS
display

11. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
Examples of AIS information
displayed on a marine chart
Slide 11
Chart Plotter/AIS Black Box… Versus Standalone AIS
Example of AIS information
displayed on a dedicated
AIS Display

12. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
Antenna Selection and Installation
Slide 12
Antenna Installation Tips:
• Mount as high as possible, ideally 2-3m (6-10 ft) above the water
• Don’t mount in radar beam
• Should not be collocated with any other antenna
• Ideal mounting separation between antenna is 3 m (9.85 ft)
• It should be an omni directional marine band VHF antenna
• Don’t mount in the shadow of structures, masts etc
• When using an antenna splitter ensure it is an active AIS Splitter to
protect the device that is not transmitting.
AIS antenna
VHF radio antenna
VHF & AIS antenna
AIS signals can be received on most standard
marine antenna operating on VHF frequency 156
to 163 MHz.
Optional specially tuned AIS antenna are
available as stand alone aerials.
Alternatively a single VHF antenna can be used
with the antenna being shared using a VHF/AIS
Splitter with one tail going to the VHF radio and
the other to the AIS device.

13. © Copyright 2011, Vesper Marine Ltd – Confidential, Not to be copied
Why will AIS use Continue to Grow?
Slide 13
Individual End-User Drivers:
• Personal safety
• Collision avoidance and situational
awareness
• Boat investment protection
• Improved ship to ship communication
Common Good Drivers:
• Security of coastlines and sovereign areas
• Search and Rescue (SAR) needs of nations
• Environmental impact monitoring and
enforcement
• Shipping traffic management
• Collision avoidance and situational
awareness
CommunityNeedsPersonalNeeds

14. For more information or to request an original
electronic version of the slide deck please
email us at info@vespermarine.com