Friday, 18 October 2013

Automatic Identification System (AIS) Update for Cruising Sailors and Yachtsmen

To all our readers my apologies for the layout and quality problems of this post. There is currently a glitz in the Blogger software which affects some blogs and not others. Google are working on the problem so hopefully they will have a fix shortly. Meanwhile, here goes for this issue of sailboat2adventure blog.  

AIS (Automatic Identification System) is raising its head again. We have discussed previously in several posts the benefits of this system and the value of it for recreational sailors to have it installed in their vessels. Technology moves ahead at such a rapid rate nowadays that you only have to turn around and Boom! the up to the minute equipment you bought yesterday has already been superseded by a not only more advanced or integrated model, but also possibly somewhat cheaper!
Vesper Marine XB AIS transponder
We have conjectured in the past that AIS would be integrated into chart plotters and it already has. Then we had the arrival of AIS apps for smartphones and we have looked at those also. Now, we have a New Zealand company, Vesper, manufacturing and marketing very user friendly AIS transponders which appear to be sweeping the market for installations in recreational craft, especially sailing vessels. You can take a look at their range on their website

Vesper Marine Watch Mate AIS transponder
The current debate raging is whether or not to have the AIS integrated into the chart plotter or have a dedicated stand alone installation. As in all things everyone has differing opinions and here are a few postings you can view on Cruisers Forum:

Read with interest and make your decisions based on your requirements for your vessel.

As a refresher have a look at this extract from Wikipedia showing the wealth of data that AIS can deliver to the cruising sailor:

Broadcast information 
An AIS transceiver sends the following data every 2 to 10 seconds depending on a vessel's speed while underway, and every 3 minutes while a vessel is at anchor:
  • The vessel's Maritime Mobile Service Identity (MMSI) – a unique nine digit identification number.
  • Navigation status – "at anchor", "under way using engine(s)", "not under command", etc.
  • Rate of turn – right or left, from 0 to 720 degrees per minute
  • Speed over ground – 0.1-knot (0.19 km/h) resolution from 0 to 102 knots (189 km/h)
  • Positional accuracy:
    • Longitude – to 0.0001 minutes
    • Latitude – to 0.0001 minutes
  • Course over ground – relative to true north to 0.1°
  • True heading – 0 to 359 degrees (for example from a gyro compass)
  • True bearing at own position. 0 to 359 degrees
  • UTC Seconds – The seconds field of the UTC time when these data were generated. A complete timestamp is not present.
In addition, the following data are broadcast every 6 minutes:
  • IMO ship identification number – a seven digit number that remains unchanged upon transfer of the ship's registration to another country
  • Radio call sign – international radio call sign, up to seven characters, assigned to the vessel by its country of registry
  • Name – 20 characters to represent the name of the vessel
  • Type of ship/cargo
  • Dimensions of ship – to nearest meter
  • Location of positioning system's (e.g., GPS) antenna on board the vessel - in meters aft of bow and meters port of starboard
  • Type of positioning system – such as GPSDGPS or LORAN-C.
  • Draught of ship – 0.1 meter to 25.5 meters
  • Destination – max. 20 characters
  • ETA (estimated time of arrival) at destination – UTC month/date hour:minute
  • optional : high precision time request, a vessel can request other vessels provide a high precision UTC time and datestamp
 In light of all this valuable information delivered to you on your screen, it is difficult to mount an argument against installing AIS in your boat.

AIS data extract courtesy Wikipedia, images courtesy Vesper Marine 

You can read much more about the cruising lifestyle in my book ‘Sailing Adventures in Paradise’ downloadable from my website

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