Automatic Identification Systems

Report Text:

I am a yachtsman who sails in the Solent, cross channel and around Brittany and have radar and AIS fitted on my vessel.

I am very concerned about the vessels I have observed travelling in shipping lanes and cross Solent ferries which are not transmitting ANY AIS signals.

CHIRP Comment:

CHIRP has received reports from time to time about vessels which are transmitting incorrect information, typically large errors in the Heading.  However we have not received previous reports about ships that are not transmitting an AIS signal.  CHIRP is therefore keen to learn whether non-transmission is a frequent occurrence.  If you do observe such an occurrence, please send us a report.

As this report mentioned the Solent ferries, we have checked the publicly accessible AIS website on a number of occasions and ascertained that the Solent ferries have been showing their AIS signals.

In further communication with the reporter, we were given further specific details of an occasion last year when a specific vessel was not giving a signal because, reportedly, the equipment was undergoing servicing.  With the passage of time since then, we have not determined the particular circumstances. It is however appropriate to make some general comments regarding AIS.

Subject to further reports we may receive, we are currently inclined to think that the commercial vessels are generally transmitting an AIS signal, but recognise the possibility that there might sometimes be isolated failures.  There may also be the possibility that there may be a technical problem with individual AIS receivers on small craft, but CHIRP has not received previous reports to indicate that this is a general issue.

We suggest the following as the way forward:

1. If you can identify a vessel that is not transmitting an AIS signal, call her on the VHF and advise them. Such intervention gives the vessel the opportunity to rectify it immediately.
2. If there is no response from the vessel, or if you cannot identify her, advise the Coastguard immediately by VHF. This gives the Coastguard the opportunity to check and contact the vessel.
3. In any event, CHIRP would be pleased to receive a report of the incident. If the identity of the vessel is known, we would follow-up with the manager. We generally find that shipping companies, including the Solent ferry companies, appreciate receiving reports on safety issues so that they can take corrective action.

As further information, the regulatory requirements for fitting of AIS are subject to a phase-in timetable.  The full details are available on the MCA website under SOLAS V regulations, Chapter 19 (Shipborne Navigation Systems) and Annex 17.