Monday, 18 June 2018

Dangerous AIS Targets? New Challenges To Safe Navigation

A Busy Waterway, However The AIS Fish Beacons Give Me Great Fears

Heading north around Cape Hatteras a few weeks back, we found ourselves facing a number of targets along our intended course - only some were more dangerous than others. That green target at top right of the image (36870200) was an American aircraft carrier performing incredibly tight turns and circles - but that wasn't the danger. Neither was the fast moving target to the left of our track (the track in black), which was the Captain Caden, a 21 meter fishing vessel out of Barnegat Bay.

FV Handful & Four Local AIS Beacons
The real danger was that tiny cluster of targets on our starboard side - the US flagged fishing vessel Handful, seen here with a cluster of AIS beacons around it (note : this image, and those that follow, is produced by replaying our voyage on our electronic nav system. The target shapes are different when in actual navigation mode). If we zoom in (at right), the picture becomes more clear - one primary AIS target, being the fishing vessel Handful itself, plus a cluster of four AIS fish net beacons floating around her. Fish net beacons, using AIS. Hmm. OK, read my lips. Say after me. This is not good....

The AIS system was devised and built as a safety system for vessels under management. It was not built as an identification system for unmanned, unpowered fish net and long line floats that do not ask questions and cannot correct their course. If the technology is used for net tracking, the targets should display with a clearly different icon or graphic on screen. But they do not. They look just like ships on screen.

The IMO (International Maritime Organisation) has published guidelines for the display of navigation related symbols on screen (read them here) and no fishing target beacons are included. The United Nations Food & Agriculture Organisation has published a draft paper (read it here) on marking of fishing gear, which acknowledges the illegal nature of AIS fishing beacons, but doesn't come down against them.

Thanks to Ben Ellison, author of the excellent PANBO marine electronics blog, I obtained the following information from a US Coast Guard website :

"18. Can I use AIS to mark nets, pots, traps, moorings, or as a race mark, etc.? There are no outright prohibitions to use AIS (i.e. AIS AtoN) as a marker (see Types of AIS and IALA Recommendation 1016 – Mobile Marine Aids to Navigation). However, it is not permissible to do so with equipment intended for use on vessels, (i.e. AIS Class A or B devices), for lifesaving (i.e. AIS SART, MOB AIS, EPIRB AIS), or with devices that are not FCC certified and licensed. See 47 CFR §§ 2.803, 2.805, 2.301, and 80.13 regarding licensing, station identity, and the prohibition to sell, market, or use radio devices that are not FCC authorized (search, Equipment Class: AIS)." It appears then that so long as these devices are FCC approved, they can be used at sea. But are they FCC approved?

So, what has gone wrong? Firstly, Chinese manufacturers have seized on an opportunity to use AIS electronic packages as fish net beacons, though without any approvals from relevant international AIS scheme managers. Secondly, US fisherman keen to track their nets (at  very low cost) have seized on these tools and deployed them, even though they are illegal under US law (my opinion). In fact you can't buy these readily in the USA - you have to order them online through Ali-Baba or one of the foreign web supply chains.

Above is the Ova fishing buoy beacon, sold out of China on the internet for not much over US$100.00, waterproof to 10 meters, and it comes pre-programmed with it's own MMSI number. Wait a minute - how did that happen? An MMSI number is supposed to be a Maritime Mobile Service Identifier - a number that identifies a vessel and an owner and tracks back to the national registration of the identified vessel.

Who ever heard of MMSI numbers being issued by the factory that built the product.... geez. They are supposed to be issued by the country of registration!

Then there are other brands and models - in fact there are so many models that there is an entire market place on the web where you can buy these (illegal) devices. Check out the page at this address. Many are shipped with software on disk plus a cable that allows the user to program the MMSI number - this is completely illegal under US FCC regulations.

Many fisherman, reading this story, will be wondering what the heck I'm complaining about - OK so it's illegal, but where is the harm? In fact it can be said that the fisherman are doing us a favor by identifying nets and floats that otherwise would be invisible to us at night. However until these beacons can be identified easily on screen as floating beacons (and not ships), then I believe that some dangerous situations are being created. Read on for the story on that ....

Illegal AIS Fishing Beacons - The Problem
941 Prefix Is Illegal Transponder

The image at right shows us approaching a series of the illegal buoys - there are five in evidence here, though in reality their were eight AIS markers attached to the fishing lines. Of course we didn't know they were beacons - we thought it was a fleet of fishing boats ... the system doesn't provide any discrimination on screen.

Problem is, they are so low to the water that the signals also drop in and out constantly, with no consistancy on the screen of the approaching vessel. It's very confusing.  Further, most of these net or line arrangements have an escort vessel that keeps an eye on the harvest - yet in this case the fisherman responsible did not even put a proper AIS transponder on the escort boat.

Flying up the gulf stream at night, we had numerous intermittent AIS targets that we could not see or correlate on radar, plus one obvious boat target on radar that did not even have an AIS transponder.

Now, please look at the fast moving target (number 211801000) heading straight into the array of illegal targets. At about 18 knots. We spoke with the officer of the watch on this ship (Northern Monument, a 300 meter container ship) and asked if he knew what these targets were..... his response is truly sobering, and scary. "Ï'm not sure what they are, I am so confused". He was confused enough to hold course and plow on through the target area- maybe he dragged a few illegal buoys down and destroyed them.

The issue here is that we really don't want ship captains being so confused that they ignore AIS targets in front of them and just plow on without care. Really, what is the point of a safety system that is no longer safe?
Targets Appearing Dead Ahead

Illegal AIS Fishing Beacons - Observed Behavior

These little beacons have up to 5 watts of power, so in theory they should be reliably visible for some distance. But that is not the case - because they exist very close to the water level, they tend to drop in and out on our viewing screens, sometimes there, sometimes not. The closer we get to them, the more difficult they are to receive.

This isn't a problem for the fisherman - they already know the general area they are searching, however it is a problem for other navigators.  They can pop up at the last possible minute, right in front of you - and when you look ahead in daytime nothing is there, and when you look on radar nothing is there.  Suddenly the whole AIS system reliability is thrown into question. On screen, they look like a fleet of ships, when you can see them.

In the image at right the fishing boat Sea Angel is attending the nets, however that target right in front of our bow has just popped up. We really didn't have time to avoid it, and it went past on port side about 10 meters away.

Professional fishing friends tell me that these transponders were not actually attached to nets - rather it was Mahi Mahi season on the coast, and the transponders were on baited long lines attracting the big Mahi fish.
Two Ships On Port, Two Illegal Targets Ahead

At this point  I need to re-state the obvious :

- The AIS system was built to enhance safety for ships at sea
- In the USA, all AIS devices must be programmed and identified by the dealer or installing technician - End users must not be able to program the MMSI number.
- AIS beacons are now manufactured for other applications, such as personal man overboard emergencies.
- However there are no industry standards (that I'm aware of) that support AIS technology being used for tracking nets or long lines.

It is unfortunate that these illegal beacons are being purchased by fisherman and deployed in shipping lanes. The result is that ships officers may now be less inclined to alter course when they see an AIS target in front of them. It's a massive step backward in safety for all mariners, because the illegal beacons display on screen using the same icon / graphic as a normal boat. Many of the beacons we observed were programmed with the name of the escort vessel - so they displayed a ship name and graphic. Very confusing and likely to cause an accident at some point.

After forwarding this information to the US Coast Guard we received a very prompt response from them, as follows : "given their use of an illegitimate MMSI number(s) and other erroneous data in their broadcast it is most likely that they are one of the illicit devices also shown on your webpage. We are well aware of the proliferation of these devices, notwithstanding our and the FCC best efforts to shutdown outlets that have tried to sell here in the U.S. Next month we are poised to publish a Public Notice which will hopefully get the word out to their users, and heed them to cease and desist. Note, these and other Autonomous Maritime Radio Devices (AMRD) are a worldwide issue being addressed at the International Maritime Organization and International Telecommunications Union (see attached). Hopefully, in the not too distant future we will have a better paradigm for their legitimate use, beyond what is already permitted under the AIS Aids to Navigation station approval." So it appears the USCG is on the case, and things may improve in the future.

Last night I had dinner with a US east coast professional fisherman, a friend, who also believes these beacons should not be in use. He's on his way to La Jolla (CA) this weekend for a board meeting of the Seafood Harvesters group, and will raise this issue with them. That group includes representatives of all the commercial fishing operations around the USA. Not sure what will come of that, but it's another pressure point to get things moving.

This whole situation can be rectified if the AIS system governing bodies will agree on a unique display icon / graphic for fishing beacons - that way we could sort out the big dangerous targets from the smaller (less dangerous) targets. Right now its a confusing and dangerous mess.


  1. This comment has been removed by the author.

  2. This comment has been removed by the author.

  3. Very interesting post - thank you. But we certainly don't want to run into nets or other fishing gear. Last year 3 cruising boats in the Sail 2 Indo rally turned on their EPIRBs because of tangles with (illegal) long lines in SE Indo, & we're constantly dodging nets & pots in the Malacca Straits. Marking that junk with AIS sounds like a useful idea, but you're right that it needs to be better defined. IMHO, what we need are AIS codes for fishing gear (& updates to our AIS/nav software so we can display them properly) that allow for fishing devices to be seen & differentiated from boats & AtNs. And those devices should probably carry the MMSI of their owners (how do personal AISs work this?).

  4. Thank you for bringing this to my attention. I have of course been aware of the AtoN topic and "virtual buoyage", which, being regulated and, presumably, standardized, could be a boon to navigation in tricky areas, but this is not that. It's just a greedy, opportunistic exploitation of an existing system that risks degrading it to the point of uselessness. Why, yes, I just installed a Vesper XB-8000.

  5. The fish marker AIS's are pretty common (100's)in the East and South China Sea. They are a bit annoying because they clutter the radar screen but once they're understood to be fish markers, they're not that big of a deal

  6. Thanks for the very interesting and informative post ... I would point out 1 useful piece of information here. All the The "odd" targets you saw had an MMSI started with 941 (in the graphics.) MMSI's are kind of like phone numbers, with area codes. The first 3 digits are the maritime identification digits (MID) and are assigned either geographically or by function. I have two - 1 portable, 1 fixed station) in the USA. The handheld starts 367, the fixed station 368. Numbers starting with 9 are "free-form" and do appear to be able to be set by the manufacturer. Digits 4 & 5 are manufacturer code, the balance are up to the factory to set. HOWEVER, 941 appear to be UNDEFINED. 970 is SART, 972 MOB, 974 EPIRB w/AIS, etc. 941 appears to be a rogue number BUT if you see an MMSI starting with 9, it's should be some kind of special device and NOT a vessel...

  7. I've encountered this issue a few times, the only "solution" is to check the MMSI number; I explain as "good" MMSI numbers are given by countries they have their own inicial numbers. You can check all over the web the so called MID; to not let my explanation go too long, and not going into much detail. First number 0: land station
    2-7 ship
    other numbers, like your example 9 99% chance not ship.

  8. As a future east coast 'snow-bird' I read you article with much interest.
    Thank you.


Have something to say ? Let us know your thoughts ....