[MarkSF]

Yesterday we were sailing near Angel Island, when I looked at the plotter screen, and saw an AIS target moving fast, close, and on collision course (plotter shows a dotted line of projected course for AIS targets, the length of which relates to speed).

I looked in the direction of the target, and there was nothing there. No boats at all, not for miles. The target on the screen got closer and closer, until it passed straight through us - then vanished.

If this had been a foggy day, this would have quite freaked me out. Thankfully it was a nice sunny day.

Has this glitch been heard of before, or have we witnessed the first AIS ghost ship?

I wish I had had the presence of mind to select the target and see what the name of the vessel was.

 

[Markwesti]

Submarine ?

 

[MarkSF]

If it was a submarine, it crashed quite hard into Angel Island, unless it made a very sharp turn. How would a submarine transmit AIS without a antenna above the water?

 

[MastUndSchotbruch]

Submarine ?

Extremely unlikely. If Mark did not notice it while it was passing 'through him' it would have been deep enough to prevent VHF radio to get to the surface (not that I think a sub would transmit VHF under water).

Could it be some spoofer? There is no reason why the AIS signals must correspond to a physical object. E.g. Virtual Aids to Navigation (VAtoN). It could not be too hard to 'simulate' anything that you want on the radio waves.

 

[RichH]

Please, DO report the incident to the USCG and DHS .... time, place, etc. If you have an electronic log of the phantom AIS, all the better.

 

[SVAuspicious]

Yesterday we were sailing near Angel Island, when I looked at the plotter screen, and saw an AIS target moving fast, close, and on collision course (plotter shows a dotted line of projected course for AIS targets, the length of which relates to speed).

I looked in the direction of the target, and there was nothing there. No boats at all, not for miles. The target on the screen got closer and closer, until it passed straight through us - then vanished.

If this had been a foggy day, this would have quite freaked me out. Thankfully it was a nice sunny day.

Has this glitch been heard of before, or have we witnessed the first AIS ghost ship?

AIS transmitters send out the position they are given by the navigation network, almost always from a GPS receiver. The information doesn't have to be true to be transmitted. This is how synthetic and vitual AToNs work.

In your case it could be any of a failing GPS receiver on a ship, possibly one of the DoD tests (likelihood depending on where you are), or someone purposely spoofing a ship location.

Regardless you won't be the first.

 

[hellosailor]

Some prankster screwing around with a drone?

But the web sites all showing AIS info, surely some of them are also archiving it. The USCG probably will be very interested in this, and if they aren't...CC the Commandant's Office anyway. There's a genuine DHS concern here.

 

[kwaltersmi]

What about an aircraft? Possible signal from an airplane transponder?

 

[SVAuspicious]

Some prankster screwing around with a drone?

What about an aircraft? Possible signal from an airplane transponder?

All three are extremely unlikely. Even in the unlikely event that the "ghost ship" was intentional (technically not hard but generally above the script kiddie level of pranking) there is no reason to go to the effort of a drone or other aircraft. Anyone with the technical capacity could generate such an AIS product with much cheaper means with a much lower probability of getting caught.

Frankly it isn't hard. It just requires some multi-disciplinary technical knowledge and engineering discipline. Hopefully anyone with those capabilities (and I can think of a small handful just here on SailNet) has the ethics to behave. No - I won't give anyone a step-by-step guide.

I think the more likely explanation is a GPS failure. The ship in question will deal with it in due course as will be clear to them that they are not where their GPS tells them they are.

 

[Minnesail]

 

[davidpm]

Two possibility come to mind.

A temporal rift in time. The boat you saw on the AIS was indeed there but weeks or months before or after your trip.

An alternate universe. The fact that the ghost ship went straight through your position could be explained by a simple alternate universe. It could just be a simple matter anti-matter thing.

 

[Zanshin]

The AIS signal will also broadcast a vessel name and, more importantly, a MMSI. Depending upon your plotter you might still have information from yesterday in memory. If their AIS isn't working correctly, then they should be informed. Could this ship have been on the course line their/your AIS showed, just offset by a couple of miles? Also, could your system be "buggy"?

 

[PitApe]

Have you checked the expiration date on your boat's flux capacitor recently? Just sayin.

 

[hellosailor]

Well, I think the easiest way to prank it, is to wrap some duct tape around a handheld and a drone, and send it off. Total construction time, five minutes?

But you're right, that's not needed. Anyone can feed a fake signal into the AIS network, all you need to do is feed a text file of "the plot" into an AIS transmitter, spoofing a GPS output.

Although, if you read the continuing trickle about Dark Net and Silk Road and how the feds have been getting past TOR protection to find real IP addresses...safer to use duct tape.(G)

I don't consider it a security risk to discuss something THAT blatant and simple. The security risk is that the powers that be haven't already addressed this, and won't address it unless someone really makes them look like fools.

Oh, wait...we've had that problem with spoofed unsecured emails for twenty or thirty years now, and ALL the players have managed to ignore it. Well, why should AIS be any more critical than any other poorly implemented open communications standard? At folks will know how much trust to put in it, and that's a pretty good thing.

The folks at alt2600 wrote about GPS spoofing 20? years ago. Lots of folks got upset. Someone in the military mentioned there was no reason to be upset. Anyone who was spoofing a GPS signal, was transmitting it somehow. And Uncle has these nifty gizmos called "anti-radiation missiles" that can take any broadcast signal and deliver a very loud welcome basket to it.

So, you know. AIS, drones, trust but verify, keep some eyeballs on the bridge. Same old same old as the Trojan Horse, really.

 

[TakeFive]

What OP describes could be all-too-easy to do, either on purpose or as an innocent mistake.

For instance, OpenCPN has a plugin that records and plays back NMEA instrument data. It can also share its NMEA data (both real-time and recorded) with other devices over a TCP/UDP network or Bluetooth connection. So if a guy records his track, then goes back to his marina or anchorage and replays it with his AIS transponder connected to the network, everyone within receiving range is going to see his previous track played out in real time.

I hadn't thought of this before - I may need to report it to the OpenCPN developers, since it's a potential liability if their program is abused in that way (intentionally or by accident).

 

[MastUndSchotbruch]

What OP describes could be all-too-easy to do, either on purpose or as an innocent mistake.

For instance, OpenCPN has a plugin that records and plays back NMEA instrument data. It can also share its NMEA data (both real-time and recorded) with other devices over a TCP/UDP network or Bluetooth connection. So if a guy records his track, then goes back to his marina or anchorage and replays it with his AIS transponder connected to the network, everyone within receiving range is going to see his previous track played out in real time.

I hadn't thought of this before - I may need to report it to the OpenCPN developers, since it's a potential liability if their program is abused in that way (intentionally or by accident).

I can't believe they would not disable transmission in simulator mode. If they did, you DEFINITELY should point that out to them. (I just tried to find out if they say something about it but opencpn.org is down for maintenance).

 

[MastUndSchotbruch]

Yesterday we were sailing near Angel Island, when I looked at the plotter screen, and saw an AIS target moving fast, close, and on collision course (plotter shows a dotted line of projected course for AIS targets, the length of which relates to speed).

I looked in the direction of the target, and there was nothing there. No boats at all, not for miles. The target on the screen got closer and closer, until it passed straight through us - then vanished.

If this had been a foggy day, this would have quite freaked me out. Thankfully it was a nice sunny day.

Has this glitch been heard of before, or have we witnessed the first AIS ghost ship?

I wish I had had the presence of mind to select the target and see what the name of the vessel was.

Angel Island is in San Francisco Bay, right? That should be nicely covered by marinetraffic.com. They store the information for a long time (maybe indefinitely?), so you could look up what happened yesterday.

 

[capta]

Wow, I'm so relieved I don't have AIS to worry about. I've already got two radars that can harbor 'ghost returns' and several radios that pick up transmissions that must be other worldly.
Once we're all plugged in to our HUD's, AIS's, MMSI's and FLIR's, with our GPS's directing our autopilots, we'll be much to busy to take a look around the real world with our eyes. What a wonderful experience sailing will become, don't you think? Ah, just nature, us and our tech.

 

[Classic30]

Wow, I'm so relieved I don't have AIS to worry about. I've already got two radars that can harbor 'ghost returns' and several radios that pick up transmissions that must be other worldly.
Once we're all plugged in to our HUD's, AIS's, MMSI's and FLIR's, with our GPS's directing our autopilots, we'll be much to busy to take a look around the real world with our eyes. What a wonderful experience sailing will become, don't you think? Ah, just nature, us and our tech.

AIS??? Wot's AIS?!??

 

[MarkofSeaLife]

No UFO I have ever been on has had AIS.