What are a crew’s obligations with the use of AIS — and what must you never do?
We’ve seen a bit of attention put on Automatic Identification System (AIS) lately within the maritime industry. Sanctioned cargo ships and yachts have been going “dark,” turning their AIS off to avoid tracking. Even unsanctioned, high-profile yachts have reportedly turned theirs off to avoid being tracked. What does it mean for us?
Maritime AIS is essentially what flight-tracker is for aviation. For a quick primer, AIS works via VHF, from an onboard transponder (it both receives and transmits), that shares navigation data such as speed, destination, course etc. with nearby vessels or stations in VHF range. Its primary purpose is to aid safe navigation, and coordination between vessels in high traffic areas, particularly in Vessel Traffic Services (VTS) areas. It was so effective, beginning from 2002 the IMO deemed it to be required carriage. Importantly, AIS depends on vessels’ GNSS (or commonly known as GPS) data.
Originally designed for short-range VHF, those same broadcasts are now collected by shore networks and satellites and then aggregated into the global vessel-tracking platforms we all use. It’s not a perfect picture though, and not appearing on a vessel tracking app doesn’t automatically mean AIS is off.
Under SOLAS Chapter V, when underway or at anchor, we must use AIS if it’s fitted on our vessels, which also applies on most of our tenders. The only time we’re permitted to turn it off is if its operation could “compromise the safety or security of the ship, or if a security incident is imminent” as per IMO Guidelines. Turning it off must also be done only by the master, with careful regard to any high traffic and mandatory VTS areas. In short, if turning it off, a master must be justified in doing so.
A few important takeaways on the navigational side of things. AIS data inputs can be wrong, on yours or other vessels, so it’s good practice to ensure yours are entered correctly. Similarly, the GPS position can also be inaccurate, which the AIS will transmit regardless. While both can be great sources of information, we must always check them against independent sources such as radar ranges, bearings, transits, depths and any other primary tool of navigation.
More recently, the radio frequencies that GPS (and subsequently AIS) use have been seeing intentional interference, in areas of high conflict. UK Maritime Trade Operations (UKMTO) has released reports around this electronic interference for affected areas. It has been reported within the Red Sea and Strait of Hormuz — both of which are yachting hubs and main thoroughfares for vessels entering the Mediterranean. More recently, there have also been reports in the Southern Caribbean due to recent conflicts. (You can look up heat maps for affected areas at ukmto.org.) It’s also advised to report to UKMTO any instances of electronic interference in the form of spoofing or jamming. Spoofing is when false data is intentionally broadcasted to give wrong information, and jamming is when signals are blocked completely. Jamming/spoofing affects a large area, with civilian vessels being indiscriminately affected.
The takeaway for our watchkeepers and OOWs is simply to know our AIS and GPS are great bridge instruments but can give false data. Most importantly, it’s best practice to rely on our primary means of navigation.