UK to report ships with AIS turned off

[hoolie]

The planned resolution of the new satellites was six meters

The native resolution of S-band SAR should be a lot better than that, providing the location of the satellite has millimetric precision. Difficult to predict until you have one in orbit ... ...

[CaptTom]

Originally Posted by Cpt Pat

...The data is complied once a day from AIS vessel broadcasts received by the USCG. If none of their stations could receive your broadcasts in the past 24 hours, your vessel won't appear...

Ahh, that explains it. My boat IS in the documented vessel look-up.

Originally Posted by Cpt Pat

...When I sample vessels in my area, I'm amazed that about 25% have misconfigured data

I see the same thing. Where's that 60-meter vessel? Oh, it must be that 60-footer over there!

I also see a lot of incorrect data in Class A signals. Apparently crews regularly fail to update their destination or last port, and we very often see "moored" ships doing 15 or 20 knots.

[hellosailor]

hoolie-
"The native resolution of S-band SAR should be a lot better than that, providing"
Yes, that's the key word, "providing". The native resolution of the entire system, given the variables of deployment and engineering, was expected to be six meters. That's all they were going for, and anything beyond that is a bonus. I've clearly seen the stripes in parking lots on old satellite photos that had a stated "two meter" resolution limit, and least time I checked, that meant they were getting six inches, at least, sometimes.
Punch line of a very old joke: The miracle is, the dog talks at all.

[jmschmidt]

US military ships, for reasons which should be obvious to any idiot, never operate their AIS equipment in transmit mode except in inland waters, harbors and bays of high traffic. I doubt if any other country's military, police or coast guard vessels do either.

[Cpt Pat]

Originally Posted by jmschmidt

US military ships, for reasons which should be obvious to any idiot, never operate their AIS equipment in transmit mode except in inland waters, harbors and bays of high traffic. I doubt if any other country's military, police or coast guard vessels do either.

Correct... until collisions recently took out two destroyers and cost several lives, the US Navy didn't turn on their AIS transmitters in areas of dense traffic -- a precaution that also should be obvious to any idiot. They've since revised that practice. I see them now in the Pacific traffic lanes offshore, south of San Francisco. Now they send "sorta stealthy" IDs in their AIS that require 10 seconds on the Internet to look up: they blank out the vessel's name but still send its radio callsign.

The solution is for them to passively watch AIS from other ships (both cargo ships collided with had active AIS). But I guess that was too difficult, or maybe too technical for a modern US destroyer. They could have also deployed their Mark One Eyeballs to look for traffic.

Besides the human toll, the USS John S. McCain (DDG-56) will cost a quarter billion dollars to repair. Repairs for USS Fitzgerald are estimated at $600 million. I don't know how much the US taxpayers will have to shell out to the cargo ship's owners (it was our fault). So, let's just call the costs at an even $1 billion. Your tax dollars at work!


(I can't find an emoticon here that expresses shear disgust.)

[Cpt Pat]

By the way, if you are a US taxpayer, you really should read the reports on the two collisions.

Here's the summary on both accidents (embedded within): https://news.usni.org/2017/11/01/uss...llision-report

They'll make you wanna cry out of frustration. When they gave the deck crew the same rules-of-the-road test that civilian captains have to pass with a score of 90% to operate so much as a charter with six passengers: they failed the exam.

Hopefully they never go to war, because they may all collide and sink each other.


There are a lot of reasons for this sorry state, and none that I would directly attribute to the crew: impossibly long duty shifts with grinding boredom, duty rotations that are too rapid to develop proficiency, poor and delayed training, lowered politically-correct recruitment standards, and especially lazy shore-side leadership at the top.

[Alita49DS]

Transmit AIS, like all marine equipment, is way over priced for a simple black box using VHF.

That said, it is not that expensive. Nor is it that much more than receive only.

AIS is such a great contribution to safety that there might be an argument to make it illegal to sell receive only devices.

There might also be an argument to make AIS compulsory for all vessels over, say, 10m and compulsory for it to be active.

Not that radical. No doubt years ago there was a similar argument about lights at sea. Yet this is the same issue: how best to see and be seen.

[boatman61]

Originally Posted by Alita49DS

Transmit AIS, like all marine equipment, is way over priced for a simple black box using VHF.

That said, it is not that expensive. Nor is it that much more than receive only.

AIS is such a great contribution to safety that there might be an argument to make it illegal to sell receive only devices.

There might also be an argument to make AIS compulsory for all vessels over, say, 10m and compulsory for it to be active.

Not that radical. No doubt years ago there was a similar argument about lights at sea. Yet this is the same issue: how best to see and be seen.

But.. But.. What about the Pirates.???

[hellosailor]

In 87 or 88, thereabouts, I was on a committee boat just outside NY harbor, waiting for the USN to show up and kick off the start of Fleet Week, which was then a brand new thing. Among the vessels we were expecting were a carrier and a battleship, the kind of things you'd expect to see at a distance, right?
Wrong.
Big gray ships materialized out of the gray line between the horizon and the sea and just suddenly were "THERE". It gives you a new insight into "Damned thing's the size of a battleship, how could you miss it???"
But I can understand how even an above-average idiot would have no idea just how quickly those big ships can just BE THERE in your lap. And we had a perfectly clear day, no fog, no excuses, just the usual early morning light.

[Cpt Pat]

Originally Posted by Alita49DS

Not that radical. No doubt years ago there was a similar argument about lights at sea. Yet this is the same issue: how best to see and be seen.

Yes, and there was a very similar argument many years ago over the FAA's requirement for radar transponders in light aircraft. "It costs too much, Big Brother will watch us, freedom of the skies," etc. I was a news writer for ABC in Los Angles back then, and it seemed that nearly every weekend we'd have a new story about a mid-air collision with debris landing in someone's living room. How often do you hear about that now?

You can still fly an aircraft that doesn't have a transponder (most of the gliders I fly don't have one), but only in the boondocks where your aircraft isn't likely to bump into another and then land on someone's roof.

And before that, there was lobbying against aircraft being required to carry emergency locator transmitters (basically the same thing as EPIRBs). With the same arguments about cost. The FAA made the (valid in my opinion) argument that if a little technology could drastically reduce the cost of SAR, then aircraft owners should share the burden to reduce that cost. Just look how much was spent searching for Malaysia Airlines Flight 370 (with no results) that could have been avoided if it had carried the same silly inReach or Spot beacon many of us carry on boats.

The only downside - if you want to call it that - to carrying an AIS transponder is that the CG can call your boat by name on Ch. 16 (a bit of a shock when it happens) to assist in an SAR operation. It's happened to me twice, and I don't mind one bit assisting a fellow mariner in distress. It's the traditional law of the sea, and actual law in the US. https://www.law.cornell.edu/uscode/text/46/2304

[billnz]

Originally Posted by Cpt Pat

You can see an AIS playback at: https://gcaptain.com/video-ais-anima...egian-frigate/

It appears to me that the warship was running AIS silent.

Yes, The conversation from the tanker was telling , well telling the destroyer to turn to starboard several times , by the sounds of things they seemed to have lost the plot on the destroyer. It can happen that people forget to use there 'EYE's' I think its called blinded by screens , not uncommon .

[meirriba]

Originally Posted by jmschmidt

US military ships, for reasons which should be obvious to any idiot, never operate their AIS equipment in transmit mode except in inland waters, harbors and bays of high traffic. I doubt if any other country's military, police or coast guard vessels do either.

It is my experience in the Med, that military vessels of all nationalities operate silent AIS, i.e. onle receive. It is true of other government vessels like custom vessels or marine police, coast guard etc.

[wjhutchings]

Originally Posted by meirriba

It is my experience in the Med, that military vessels of all nationalities operate silent AIS, i.e. onle receive. It is true of other government vessels like custom vessels or marine police, coast guard etc.

AIS is only compulsory on vessels over 300GT which means an awful lot of commercial vessels including fishermen don't have to carry it, therefore their thoughts are if you don't have to why should you. Also all government vessels are exempted from the carriage of AIS unless undertaking commercial operations, Chapter 5 Section 19 of SOLAS will tell you what commercial vessels carry what

[hoolie]

In the western Med a lot of fishing vessels, maybe most, do operate Class A AIS.

[gdavydov]

They are talking about ships, not boats