An AIS target can look precise on a bridge display while carrying incorrect information. A familiar vessel name, a neat symbol and a moving vector may encourage confidence, but presentation is not proof of accuracy. Every transmitting vessel contributes to the information that other bridge teams and shore stations use to understand traffic.

For the crew, maintaining useful AIS information is an ongoing operational responsibility. It includes recognising which details need human attention, which arrive from connected equipment and which changes require authorised technical support. The following approach helps organise that work without treating AIS as a substitute for a proper navigational watch.

Start with the information your vessel sends

The IMO overview of AIS explains that the system automatically exchanges identity, position, movement and other safety-related information. Begin by becoming familiar with the own-ship information pages on the installed equipment. Knowing where to find a field is a different skill from knowing whether its contents are correct.

Arrange familiarisation around the actual equipment rather than a generic checklist alone. Ask the officer being familiarised to locate the relevant information and explain where it comes from. Uncertainty about a menu or abbreviation is easier to resolve during a quiet preparation period than during a busy arrival.

Give each type of data a responsible owner

IMO’s operational guidelines, resolution A.1106(29), distinguish static, dynamic and voyage-related information. Identity and installation details differ from sensor-fed movement information and voyage entries. Navigational status requires operator attention. The guidelines also explain that an AIS built-in integrity test does not validate the accuracy of incoming sensor data.

Translate those distinctions into a clear onboard responsibility. A watchkeeper should know which routine entries they are authorised to update, which discrepancies must be reported to the master, and which settings belong with an authorised technician. A field being editable does not mean that changing it is the correct response to an unexplained discrepancy.

Make voyage changes visible

A departure delay, revised destination or changed loading condition can leave an earlier entry behind. Include the relevant AIS review in the vessel’s existing departure and voyage-change processes. Avoid creating another isolated form that competes with the information already used by the bridge team.

A useful practical question is: “What changed, and where else does that change need to be reflected?” If the answer is uncertain, assign someone to resolve it. The aim is to keep the operational picture consistent, while following the equipment instructions and the vessel’s approved procedures for the actual entries.

Treat installation changes as a reason to review

Transport Canada’s AIS safety bulletin describes inaccurate information associated with incorrectly set antenna reference points, manual input errors and sensor configuration. Its regulatory discussion is Canadian; it should not be presented as a universal rule for vessels operating in the Gulf. The technical examples nevertheless illustrate why installation details deserve attention.

When equipment has been replaced or a relevant arrangement altered, include the affected AIS information in the service close-out discussion. Ask which settings were reviewed and how the result was verified. Keep the report available to the officers who will use the equipment, particularly when maintenance and departure happen close together.

Investigate discrepancies without guessing

Suppose an officer notices that own-ship information does not agree with another bridge indication. Record the specific fields, the time and the conditions of observation. Distinguish what was seen from the suspected explanation. Avoid changing several settings at once in an attempt to make the displays agree.

Similar-looking fields may describe different things, and the equipment documentation matters. Escalate unresolved differences through the onboard process. A service engineer benefits more from a precise account of the discrepancy than from a broad statement that the AIS is unreliable. Preserve relevant evidence before it becomes difficult to reconstruct.

Be cautious about information received from others

IMO’s operational guidance cautions that AIS does not provide a complete traffic picture and should not be the sole source for navigational decisions. Accurate information from your own installation cannot guarantee accurate information from another vessel. Continue to use the required lookout, radar and other available information within the applicable collision-prevention framework.

Commercial vessel-tracking websites should not be treated as the authority for an immediate onboard diagnosis. Their displayed information may involve collection and presentation processes outside the bridge team’s control. When investigating what the installation is transmitting, agree an appropriate verification method with the responsible technical personnel rather than relying on a public screenshot alone.

Close the loop before the next watch

After an authorised correction or service visit, ensure the next officer understands what changed and whether anything remains unresolved. A brief entry connecting the original discrepancy with the action and verification is more useful than an unexplained “checked OK.” Keep the supporting report with the equipment’s maintenance records.

For assistance, send the vessel name, IMO number, AIS make and model, a clear description of the discrepancy and the intended port call. Offshore Marine Solutions can help coordinate radio and navigation equipment service. Reliable AIS information starts with careful ownership of the details: someone checks them, someone resolves uncertainty, and the outcome reaches the people standing the next watch.