200706 Close quarter situation

I am the chief officer of a very large sailing passenger vessel which was cruising close offshore from the Spanish coast on our way to Lisbon. Under light sea conditions on a bright, clear day, we decided to stop and drift in the separation zone of the traffic separation scheme (TSS) for an exercise. After reaching the planned position, we disengaged the main engine and put our AIS on 'not under command' mode. Meanwhile I kept a close look on other shipping by radar and AIS. A lookout on the forecastle was also maintained.

Within about five minutes I saw an AIS signal from a container vessel closing from far astern, steaming at 20 knots on a southerly course. The CPA was 0.02 nautical miles according to our AIS, and the radar indicated a similar CPA. The TCPA at that moment was 38 minutes.

I decided to contact the ship by VHF on channel 16 since we were stopped and drifting, just to make sure they had our data on their AIS. As they didn’t answer my call, I sent a text message on the AIS. When this, too, did not get a response, I sent them a DSC call. The ship came into view at about 10 miles. After the second unsuccessful DSC call, the distance was less than seven nm and with the same CPA, I decided to call all hands, aborted the exercise, re-started the main engine, put the AIS back on 'under way using engine' and resumed our southerly course at about seven knots. Very soon, we were overtaken on our starboard side at a distance of 0.4 nm by the container ship on a parallel course. Once again I attempted calling her on channel 16 and on DSC, without getting any response.

I teach seamanship at a nautical college and I always urge my students to pay extra attention to the rules, 'never leave the bridge unattended' and 'under all circumstances maintain a proper lookout'. These rules were obviously not being followed on the container ship.

Editor’s note. We must all do some soul-searching as to why such instances of poor watchkeeping standards keep recurring. The sailing ship, however, ought to have selected a more open sea area for conducting the exercise, as the Colregs require all vessels to 'avoid entering a separation zone' unless it is necessary to avoid immediate danger.

FEEDBACK 1 - April 2007

This report referred to another case of a speeding container ship passing very close to a large sailing vessel, which was forced to abort a safety drill while drifting and parallel the course of the container ship due to lack of response to bridge-to-bridge and AIS calls.
It was wrongly implied that the sailing vessel stopped for the drill in the ‘traffic separation zone’. In fact, what the reporter wanted to say was that the location was on a ‘theoretical line’ joining the two TSSs off Cabo Finisterre and Lisboa, separated by 200 miles of open sea.

As a result, the editor’s note that the sailing vessel should not have entered the ‘separation zone’ is incorrect. The error is regretted: Editor

FEEDBACK 2 - October 2007

This report concerned a large passenger sailing vessel drifting in open waters on a calm, clear day while carrying out an exercise after selecting the NUC (not under command) mode on her AIS. She reported that a large container vessel that was heading for a close quarters situation failed to respond to VHF and AIS messages requesting wider berth. When the range was seven miles and closing fast, the sailing vessel aborted the exercise and re-started her engine and paralleled the other vessel's course. The container ship passed at 0.4 NM range and never responded to the voice and text messages.

It is, of course, regrettable that, in all probability, the container vessel may not have been keeping a good lookout.
There are a few other points of interest:

Whether the reporting sailing vessel was truly NUC is debatable - a vessel stopped and drifting (to conduct a drill, to delay her ETA, etc), to the best of my knowledge, may not strictly be NUC
Expecting a vessel to take action 12 miles away may be unrealistic. Most seafarers (and maritime lawyers too, if court decisions are anything to go by) would take avoiding action 6 miles away or 10 minutes before CPA
AIS messages may not be the most prudent way to avoid collisions.
It would be interesting to hear the views of others regarding this.

FEEDBACK 3 - December 2007

The sailing vessel did not meet the definitions of a vessel 'not under command' as any inability to manoeuvre was not through exceptional circumstance and as the event proved, the vessel was able to manoeuvre as required by the rules by starting the engine. Just because a vessel's engine is shut down does not bestow the status of NUC. However, if the engine had broken down that would be another matter.
Similarly, the vessel couldn't be considered to be restricted in ability to manoeuvre as the nature of the vessel's work did not restrict the vessel from manoeuvring. In this case, the distinction between the vessel's work and the work of the crew is important. A drill falls into the category of the work of the crew not of the vessel.
It was the decision of the master to shut down the means of propulsion and conduct a drill. Therefore the vessel is still obliged to comply with the rules as for any other vessel that is underway.
The vessel complied with the rules by maintaining a proper look out (Rule 6), assessing the risk of collision (Rule 7), and taking action as the stand on vessel (Rule 17).

An article by Captain Chhabra (Seaways/Sept 2006) touched on a similar point by noting a power-driven vessel inappropriately claiming NUC status while stopped and waiting for orders. Would not a sailing vessel with an engine be essentially the same as that power driven vessel (as regards NUC status), having power available but electively not engaged for propulsion?
Farwell's Rules of the Nautical Road (US Naval Institute Press) eighth edition notes that 'NUC ... may also include sailing vessels becalmed and without means of propulsion'.
Interestingly Farwell, in a footnote, makes reference to a MARS 200209 which in turn references MGN 152. One paragraph of this reads: 'In some cases, vessels erroneously or falsely display NUC signals when their main engines or auxiliary machinery are shut down for reasons other than breakdown or necessary maintenance.'
But as for the container vessel - given that over the 14 minutes plus period of the approach, she ignored two VHF calls, one AIS text message, three DSC calls and although passing at 400 yards, demonstrated no visual awareness of the large sail vessel's existence despite 10 mile visibility. I would go substantially farther than '....it is, of course regrettable that, in all probability, the container vessel may not have been keeping a good lookout'. I think no one was home.

(Although AIS did not play a significant role in this incident, this writer warns of the dangers in using AIS as a principal means for collision avoidance and for distinguishing between innocent and hostile craft: Ed.)

As with radar - assisted collisions, navigators need to be vigilant against AIS-assisted collisions! Inaccurate human programming of data appears to be the main problem. AIS-assisted collisions have occurred where AIS data had been relied upon and later found to be inaccurate. A prudent navigator who uses his ARPA or radar properly, would easily identify a 'stationary' target, instead of 'assuming' it was moving, as falsely indicated by the AIS. The Fairplay journal supplement, Solutions of October 2007 mentions that mariners passing through the troubled waters of the Middle East are being asked to leave their AIS units turned on. The combined forces rely on the AIS information to identify friend or foe, so presumably, if the patrolling 'friendly' naval or coast guard vessel observes a vessel by other means and without an accompanying AIS ID to match the position, the likelihood of a shot across the bows is a distinct possibility.