Met a cargo ship with no ais?

[JPA Cate]

On my watch, I encountered a ship with no AIS signal, but following him off to a different VHF channel, someone aboard the ship was making arrangements for the repair of one at the next port. From this, I gathered they knew it was not working, and were planning to remedy the situation.

Much worse, from my point of view was the time a small ship approached us at night--unlit. After it had passed us, about 1/4 mile, it changed course, and a very loud siren noise came from it: whooop! Whoop! Whoop! about 15 times. I actually hailed them on the VHF. "Unlit ship with siren on, do you require assistance?" There was no answer. Quite unsettling, actually.

Ann

[requiem]

Originally Posted by ArmyDaveNY

This is a brief synopsis of the threats:

https://www.trendmicro.com/en_us/res...g-systems.html

N.B. I am not suggesting that AIS failures and corruption are common place. I am suggesting that it is likely happening in small amounts and we are likely to see more issues as individuals play with it and discover ways to use it, some of which will be unapproved.

Just skimmed the synopsis and yes, it's about what I expected. About all that's left out are some of the "hows" but suffice to say that most of these attacks appear trivially simple to carry out (and incredibly so compared to GPS spoofing). I wouldn't say it's a "we now know" thing, more of a "we know, we just don't talk about this" sort of thing. SDR technology has unfortunately made that approach even less tenable.

[kvstein]

Last year I was passing close to Mar-a-Largo. I was motoring on calm night to go from Vero Beach to Miami. I was running close to shore to pick up a counter current to the Gulf Stream. About midnight a large, well lite boat fell in behind my course. It was not broadcasting AIS. It broke off contact after several miles. Just sayin'.

[lo2jones]

Here in San Francisco Bay, very explosive cargo ships are occasionally not on AIS and are escorted by a flotilla of USCG ribs with their 50 caliber guns mounted and ready. Next time, call VTS on the radio, let them know, and don’t lose anymore sleep over it.

[Oliver]

I learned many years ago how careless watch keeping can be on commercial ships mid-Atlantic. I was aboard a passenger freighter bound for NYC from the Med. We were two days out. It was night and some of the passengers had a roaring party going when one of the young mates suddenly walked in. He poured himself a drink and began to flirt with one of the young attractive women. "Aren't you supposed to be on watch on the bridge," I asked? He explained that indeed he was but that the heard the music and decided to take a break. There was no one on the bridge on a large freighter making 16 knots!
Oliver
Southern Lady

42 Grand Banks Classic "Woodie"

[edlepera]

Always remember the ColRegs rule 5. Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and or the risk of collision.

[boat driver]

Originally Posted by kvstein

Last year I was passing close to Mar-a-Largo. I was motoring on calm night to go from Vero Beach to Miami. I was running close to shore to pick up a counter current to the Gulf Stream. About midnight a large, well lite boat fell in behind my course. It was not broadcasting AIS. It broke off contact after several miles. Just sayin'.

that was something recreational. large commercial traffic must remain offshore >5 miles around Florida unless approaching port. pollution safety.

[jlb]

Originally Posted by kvstein

Last year I was passing close to Mar-a-Largo. I was motoring on calm night to go from Vero Beach to Miami. I was running close to shore to pick up a counter current to the Gulf Stream. About midnight a large, well lite boat fell in behind my course. It was not broadcasting AIS. It broke off contact after several miles. Just sayin'.

It is possible the boat was transmitting encrypted AIS making it difficult for your receiver to plot it. I occassionally see encrypted AIS transmissions near SF Bay.

[Kilkern]

I've seen this in the Solent (UK) as well, but found later that they were transmitting, but the receiver on my yacht was perfectly in sync with the transmitting ship, unfortunately always on the opposite channel. The AIS receiver I had didn't listen simultaneously on both AIS channels.

[JBsurfin]

Originally Posted by JebLostInSpace

So I was on my way into the Chesapeake-delaware canal this morning. I was keeping a pretty close eye on AIS since I didn't really want to meet a big cargo carrier at the entrance, so I was quite surprised to see one as it rounded reedy island. A close look confirmed they were definitely not broadcasting their position on AIS. That's the first time I've ever seen one not broadcasting, and my understanding is those ships are required to by law.

I hailed them on the radio. No response on 16, but they answered on 13. I asked if they were aware they weren't broadcasting, and captain said they were aware. Didn't get any more info than that, so I'm just super curious about it. Equipment failure maybe? Any other guesses?

The ship was probably about 300 feet, carrying containers, and under way out the delaware Bay

https://www.navcen.uscg.gov/?pageNam...equirementsRev

[Paul L]

Originally Posted by jlb

It is possible the boat was transmitting encrypted AIS making it difficult for your receiver to plot it. I occassionally see encrypted AIS transmissions near SF Bay.

How do you know they are transmitting in restricted mode, encrypted? Why would a ship use that mode in a busy area like San Francisco Bay approach?

[jlb]

Originally Posted by Paul L

How do you know they are transmitting in restricted mode, encrypted? Why would a ship use that mode in a busy area like San Francisco Bay approach?

How: By looking at the 1371 fields
Why: At least one was traced back to SF Police.

[Jim Cate]

Please explain what the purpose of sending an AIS signal that no one can decode might be? Makes no sense upon first examination, but perhaps I'm missing something.

Jim

[ussvdharma]

AIS is great, but it can NOT be relied upon 100%,,,Your radar with a warning zone should have alarmed to notify you that someone was on a collision course or near.

[jlb]

Originally Posted by Jim Cate

Please explain what the purpose of sending an AIS signal that no one can decode might be? Makes no sense upon first examination, but perhaps I'm missing something.

Jim

Possibly to share your location with people you trust and hide it from (low tech) untrusted individuals.