UK to report ships with AIS turned off

[DefinitelyMe]

Originally Posted by jasbee

When we sailed through Indonesia in 2013, we several times experienced ships at night which turned their AIS transmitters off as soon as they heard our VHF transmissions. Our first question was always "have you seen us?". We had some near misses. Not to mention smaller vessels not required to have AIS and which often had no lights or incorrect lights. We would not want to sail there ever again.

Yea, we just left Indonesia and I can report that not much has changed. We quickly discovered that they simply don’t give a %@&#. Lights, sounds, in fact colregs in general simply don’t exist there. They will always pass in front of you if they can in order for them to reduce the possibility of picking up bad spirits in your wake. The inter-island ship captains are, frankly, dangerous idiots who should not be responsible for an inflatable dinghy let alone a cargo ship. But, that’s the way it is and it seems to work for them.

The first Indonesian vessel we encountered was a fishing boat a few hundred miles out from Saumlaki. It was aiming for us. I changed course and they changed too to keep us on a collision course. No radio response, no AIS, nothing. I ended up putting out an all-ships broadcast of suspicious activity. I was getting pretty nervous! One of the international cargo ships responded and the guy just said “go to ch. 6 and I’ll let you know how things work here”. After that I just assumed nobody was going to do the right thing and then it all went much more smoothly!

Sorry, I digress. I think it’s cool that the U.K. are looking at doing this. And yes, even our little class B transponders transmitting at 2W reach the satellites easily. It’s how websites like marinetraffic.org get their data apparently.

[Cpt Pat]

Originally Posted by S/V Alchemy

Actually, that's how Marinetraffic.com often works in harbours: shore-based stations poll AIS transmissions and plot them on the webpage maps. That how I can tell my boat hasn't been stolen from its dock...I can see it online! (For the record, there are not a lot of Class B AIS units in Toronto Harbour; I think there's three at my club and in busier places, I wouldn't leave the AIS on when not aboard the boat as that just creates clutter.)

I run a marinetraffic volunteer receiving station (https://www.marinetraffic.com/ais/details/stations/595), so a couple of technical points:

> shore-based stations poll AIS transmissions and plot them on the webpage maps

There is no polling involved. The AIS stations transmit automatically (at rest, every 3 minutes, when moving - more often). Many volunteer marinetraffic AIS stations use inexpensive receivers that have no capability of transmitting a poll.

> I wouldn't leave the AIS on when not aboard the boat as that just creates clutter

AIS is capable of handling 4,500 stations within any 20 mile radius. And if there are more, the radius just gets smaller. It's a really elegant system for sharing frequencies. As far as cluttering people's displays, if they have a good display (like Vesper Marine models), all AIS targets except those that are a potential collision hazard are filtered off the screen.

Turning the transmitter off makes your vessel suspicious. A little known feature is a report (polled by the CG) that tells the authorities how long your transponder has been powered up on the same MMSI. What they're looking for are "MMSI swaps" between vessels that are indicative of spoofing associated with smuggling. That's one reason why Class B transponders don't permit the user to change the MMSI (the other reason is they don't trust ordinary users to not muck it up). if two vessels turn off their transponders in port, and either one turns their transponder back on and gets underway, the CG can reasonably suspect they may have swapped MMSIs, or actual transponders.

If you don't want to invite a boarding, first have an AIS transponder (the bad guys don't like being tracked) and, never turn it off (unless you're concerned about Captain Blackbeard and his band of merry pirates boarding you). If you're sailing the Somali coast, the authorities will understand your switching it off.


Before we all get wrapped up in paranoia about some sat ratting us out for maybe conserving our batteries at sea: voluntarily equipped (recreational vessels) are never required to transmit their position on AIS.

[Cpt Pat]

Originally Posted by DefinitelyMe

Yea, we just left Indonesia and I can report that not much has changed. We quickly discovered that they simply don’t give a %@&#. Lights, sounds, in fact colregs in general simply don’t exist there. They will always pass in front of you if they can in order for them to reduce the possibility of picking up bad spirits in your wake. The inter-island ship captains are, frankly, dangerous idiots who should not be responsible for an inflatable dinghy let alone a cargo ship. But, that’s the way it is and it seems to work for them.

Are you sure you're not talking about the San Francisco Bay on a Saturday?

[sy_gilana]

Just to clear up a misconception. Class B offshore data is in the satellite derived databases. Its not talked about much, but its there.

[Cpt Pat]

Originally Posted by sy_gilana

Just to clear up a misconception. Class B offshore data is in the satellite derived databases. Its not talked about much, but its there.

Class B data is also in the US Coast Guard database, provided the vessel has been seen by a USCG Vessel Traffic Service station. Check it out: https://www.navcen.uscg.gov/aisSearch/index.php

[blubaju]

Sorry, wrong, some countries in Asia insist on AIS transmitters even on small recreational vessels.

Eg: It is mandatory for yachts to be equipped with Automated Identification System (AIS) prior to entry into Singapore waters. The AIS transponder must be approved for use within the port by the MPA or the Port Master. E-mail the vessel information to noa@mpa.gov.sg at least 12 hours before entering Singapore waters.

[billnz]

Originally Posted by kas_1611

The article states -

"The satellite is equipped with a receiver that can pick up Automatic Identification System (AIS) radio signals.
These are the positional transmissions that large ships are obliged to broadcast under international law.
Vessels that tamper with or disable these messages very often are engaged in smuggling or illegal fishing activity.
If such ships appear in NovaSAR's radar pictures, they will be reported to the authorities."

Pretty clear to me.

I wonder if that would have helped the norwegian destroyer who hit the tanker last week

[billnz]

passed frew raffles marina recently , never even mentioned AIS , pretty slick operation at the clearing desk.

[billnz]

Singapore the same just give way to everything , even the guy on the rickshaw.

[CaptTom]

Originally Posted by Cpt Pat

Class B data is also in the US Coast Guard database, provided the vessel has been seen by a USCG Vessel Traffic Service station. Check it out: https://www.navcen.uscg.gov/aisSearch/index.php

Couldn't find my boat, by call sign, MMSI number or documentation number.

Where does this information come from?

[blubaju]

Maybe its like with our ships registration, never checked , no survey, until are involved in an accident. Then you better have everything needed

[transmitterdan]

Originally Posted by CaptTom

Couldn't find my boat, by call sign, MMSI number or documentation number.

Where does this information come from?

Try entering your vessel name here:

https://www.st.nmfs.noaa.gov/st1/Coa...selByName.html

Then look for your home port in the listing to find your particular vessel if there are a lot with the same name. Also, there is a link on that page to search by official ship's number which should be unique.

[Cpt Pat]

Originally Posted by CaptTom

Couldn't find my boat, by call sign, MMSI number or documentation number.

Where does this information come from?

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. If it's in port, the CG may not be able to "see" into your port. My port is surrounded by mountains, and although only 20 miles from San Francisco, we barely get FM broadcast stations, no TV stations and very marginal CG reception on VHF ch. 16. Only about half of the vessels with operating AIS appear in the database, I presume because of varying antenna heights.

If other AIS-equipped vessels nearby do appear in the database (you can look them up by vessel name), your AIS transponder is broadcasting, and you don't appear in either the CG database or the marinetraffic maps: you may have a problem. I'd ask my neighbors if they see my vessel on AIS when they're a reasonable distance away (a mile or two).

The purpose of the page isn't intended as a "radio check" but instead as a validator for correctly entered AIS data. When I sample vessels in my area, I'm amazed that about 25% have misconfigured data (and most skippers probably paid someone to configure that data). None of your data should appear in red type.

(I have one disagreement with the validator: if your GPS antenna is offset all the way to your port or starboard side, and you enter the distance for that side as zero, the validator reports the configuration as an error.)

The data is derived from both your data being broadcast by your transponder and FCC data retrieved by correlating your FCC assigned callsign. The Vessel Flag is derived from the first three digits of your MMSI (the country prefix). The "Owner" data comes from the FCC license. If you don't have a license and call sign, that information will be blank. Class B transponders don't report draft or the positioning system. Here's an example screen for a Class A transponder (Ad Astra) and a Class B transponder (Pacific Snapper)with no assigned (or configured) FCC callsign:

[Cpt Pat]

Originally Posted by billnz

I wonder if that would have helped the norwegian destroyer who hit the tanker last week

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.

[hellosailor]

The planned resolution of the new satellites was six meters, but the big news was that they have been able to get back images with higher resolution, right out of the box. So they can say "There's a boat down there, it might be your missing 35-footer" even if they can't tell just what they are looking at.

But the point of the "no AIS" reports is that one can presume vessels of a certain size are usually commercial vessels, and with a little database crunching, the authorities can say "Yeah, we had a fifty foot trawler go black three days ago, and now we've got a boat that same size in the no-go area..."

The purpose is to guide patrol vessels to "black" vessels that might be illegally fishing (or smuggling) in order to perform actual intercepts. And simply KNOWING there's a vessel over a certain size, in a certain area, gives them a huge advantage. Especially if it appears to be trawling, not just heading from "here to there" in a direct line.

It puts the game up a notch.