AIS. Lies & Misconceptions

[Peppermint]

I'm getting a vibe about AIS that shows a fundamental misunderstanding of what it's all about. To many people are using AIS & Radar in the same breath

An add in the March 2005 YM states

AIS Radar
" All vessels over 300 tonnes and all passenger vessels must now carry an AIS transponder."

Well thats simply wrong. Vessels up to 500 tonnes that don't go foreign are exempt. Implimentation for foreign going vessels is not going to be completed until 1st of July 2008. Warships don't use them. Many ships turn them off or suffer malfunctions.

The implication from this advert is that AIS is some sort of radar substitute. It's not. It's a commercial/security/administration system that even when it is fully implimented will offer cold comfort to yachtsmen on a foggy night in the channel.

 

[AlexL]

There is a story in some quarters also at the moment that many ships are turning off the AIS transmitter for security (mainly in the far east) and commerical reasons (when they get near a port with a big load - they don't want the commodity markets knowing!) so a panacea it ain't.
A usefull ADDITION to Radar it is.

If anyone has ever seen an Air traffic control secondary surveillance radar, they will see the potential benefit of AIS. In air traffic a normal radar picture is overlayed with Transponder data (Altitude, id codes etc). If a transponder is not carried then the radar blip still appears.
I can see AIS being the same sort of thing, where the RADAR gives the primary info with AIS info being added as a secondary source of info to assist the calculations.

 

[tome]

Afraid there are some diehards who have decided that AIS is a radar alternative, which it is not. As a supplement to radar it will be useful, as a substitute just downright dangerous.

 

[Rowana]

Get on to the advertising standards agency http://www.asa.org.uk/asa/

Perhaps we all should send them an e-mail, as this is blatently wrong and misleading.

And while we're about it, can't we have a go under the trades description act for calling ir "AIS Radar" in the first place ??

What does the fourm think ? ? ?

 

[Dyflin]

having used AIS on commercial ships, let me just say that when the AIS is switched off, it logs the time & duration of the "shut down period" and a reason for this action must be entered into the ships deck log. It is very much as a last resort in areas of piracy and <u>never</u> for comercial operating reasons. AFAIK it is a offense to do so without a very valid reason.

The other thing I noticed is that a lot of ships in the North Sea (standby boats etc) don't link it into the gyro compass and/or the gps and so it's impossible to tell what direction, speed etc. they're travelling in and so makes this a terrible substitute for radar.

~Dyflin