February 02, 2008

AIS: Friend or Foe?

First of all, let me state the obvious and the known: The Automatic Identification System for ships was supposed to be a tool to be used for functions such as Automatic Identification of ships (by VTS and shore facilities and also other vessels), whether for general information or Security purposes.

Also, let me state something which is less obvious. The possible errors within a shipboard AIS, whether the offset error or errors in initialisation or the manual feed of information, as well as the limitations of an AIS system, are ill understood by a majority of officers on board.

In an era where gizmos tend to replace basic tenets of navigation and collision avoidance, and where GPS, electronic chart systems, ECDIS and/or radars are getting more integrated, the possibility of misinterpretation and potential catastrophe is huge. Many of the same officers do not understand fully the limitations and errors of Radar or the GPS either. Nonetheless, it is not unusual these days to see almost complete reliance on such systems even while the net effect of limitations of each of the componenets is poorly understood, leading to potential cascading errors in navigation. The AIS is yet another cog in this seamless disaster waiting to happen.

In the last few years, I have experienced Officers giving the CPA from an AIS the same sanctity as that of a radar plot. I have also seen watchkeepers anticipating course changes of traffic depending on what their destination as displayed on the AIS is. Own courses have been altered in anticipation of the targets course change based on this destination, which, of course, somebody may have just forgotten to change.

In congested traffic lanes, with multiple close targets, this is a dangerous practice.

I have often seen these: wrong dimensions. incorrect mooring/underway status, , incorrect names/call signs/MMSI's. "AIS swap", similar to radar target swapping is also very common.

I have also seen pilots in European and British approaches and rivers, in fog and without, using the AIS as an easy collision avoidance tool. The name of the ship, its CPA, a short talk on the VHF with the pilot saying “you are passing 1 cable off, its ok”- easy. And this on a ship where he has stepped on board three minutes ago, has no idea of the AIS equipments reliability, limitations or errors- and has not asked anybody about those either.

I have had agents come on board in Europe and tell me, “Captain, we were watching your speed on the port AIS in bad weather. You were doing only 3 knots, so we knew you would change your ETA”. Big brother is watching you, indeed.

In the Bosphorous, I have seen ships being threatened with fines for showing incorrect AIS destinations- regardless of the elaborate VHF reporting requirements where the correct destination has been repeatedly stated. Agents used to send us, regularly, warnings about these fines.

Off the coast of Somalia, I have wondered, in an age where I can track ships via their AIS on the internet, how simple and deadly it would be for pirates to use this technology for their own nefarious purposes.-thus standing the Security usefulness on it’s head.

I have heard VHF conversations between ships, asking each other to alter course or take other action based on AIS data on CPA and destination alone.

This is a disturbing trend, which is to use the AIS and the VHF as the main tools for collision avoidance. It is not unusual to see action been taken based on these... an AIS given CPA and a VHF decided course of action. Cultural and language issues, incorrect identification of ships and others detailed above make this an action which is fraught with danger.

Clearly, there is over-reliance on the AIS. Clearly, the AIS was not meant for some of the functions it is now being put to use for. Clearly, our navigators do not understand the limitations and possible errors of this equipment. And so, clearly, we need to do something about it.

On balance, I would like to see some of these brought into effect

-A no-integration, no ECDIS/electronic chart policy unless people are sufficiently trained prior joining such a vessel. Failure to do so is contributing to phenomena like paralysis by information, a tendency to sanctify all data as equally correct and reliable, and a tendency to navigate the ship on screens with hardly even looking out of the wheelhouse porthole- what I call ‘computer game navigation’. (On one ship, I came up to the bridge to find a small fleet of sailing boats a cable and a half away in daylight and good visibility- unseen by the watchkeeper since these were not seen on the radar due to high anticlutter used, and since obviously they didn’t carry AIS, and since looking out of the porthole was apparently not in the contract. I threatened, in jest, to restrict the Officer’s certificate to read ‘Valid only on ship’s which experience no boats’ )

- ‘Hands off’ AIS installations, which mean no operator input required after initialisation except a daily check to ensure that AIS is functioning. This would mean that data like the destination is not displayed. I can’t see why this should be a problem, shore entities and VTS has enough other data confirming this, including Port clearances, vessel and agent’s declarations and VTS VHF reporting requirements. And at sea, we don’t really need to know where a ship’s destination is, except our own. Besides, this will stop the assumptions being now made with sometimes unreliable or scanty data.
This will also stop creative ways of revenue generation in some countries, like fines, for incorrect AIS input.

-The stoppage of using AIS as a collision avoidance tool by all concerned. At best, a AIS CPA may be confirmatory to a Radar plot; it cannot replace it.

Other recommendations, like improving the calibre of some Officers who seem incapable of understanding the limitations or optimal use of all electronic systems, including Radars and AIS, are outside the scope of this article.

Some of these should undoubtedly go towards an increasing unacceptable tendency at sea, which is navigation and collision avoidance by gizmo. Last I checked, most of all of these were ‘Aids to Navigation’, and that is where they must remain- useful, good aids, but not the main dish.

Or else, we will have to soon coin another term to go along with other such earlier ones- AIS aided collisions.

This post is supported by boater safety

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