What does your Class B AIS transponder do for you?

[sailingharry]

Originally Posted by chubby

big ships only show class B when there is room..

Do you know this for a fact? I strongly doubt that it would be legal. And even if the Captain wants to, in crowded areas the are usually under the control of a pilot who would be unlikely to break rules.

But I'm more interested in HOW. In busy areas in good visibility, I'd love to do this I still want to see the big boys, and have an alarm for "close" CPAs, but I'd like to turn off alarms or the entire target for Class B (or filter by size, not class -- all vessels under 100' or all vessels under 5kts or....). As near as I can tell, no commercial app or chart plotter or AIS allows this. OpenCPN does, but it has no regulatory oversight or corporate lawyers driving design decisions.

I truly suspect that the big boys are required to have all those Class B icons cluttering their screens -- and offshore they are happy for it

[rslifkin]

Originally Posted by sailingharry

Do you know this for a fact? I strongly doubt that it would be legal. And even if the Captain wants to, in crowded areas the are usually under the control of a pilot who would be unlikely to break rules.

But I'm more interested in HOW. In busy areas in good visibility, I'd love to do this I still want to see the big boys, and have an alarm for "close" CPAs, but I'd like to turn off alarms or the entire target for Class B (or filter by size, not class -- all vessels under 100' or all vessels under 5kts or....). As near as I can tell, no commercial app or chart plotter or AIS allows this. OpenCPN does, but it has no regulatory oversight or corporate lawyers driving design decisions.

I truly suspect that the big boys are required to have all those Class B icons cluttering their screens -- and offshore they are happy for it

I've never seen a chartplotter that can filter by class A/B or vessel size, but most I've seen can hide anything slower than a given minimum speed or further away than a set distance. Some may have more options. Some also have an option to hide "safe" targets, so they'll only show targets that meet your alarm criteria (such as CPA and TCPA) and hide the rest.

[hjohnson]

Originally Posted by sailingharry

Do you know this for a fact? I strongly doubt that it would be legal. And even if the Captain wants to, in crowded areas the are usually under the control of a pilot who would be unlikely to break rules.

But I'm more interested in HOW. In busy areas in good visibility, I'd love to do this I still want to see the big boys, and have an alarm for "close" CPAs, but I'd like to turn off alarms or the entire target for Class B (or filter by size, not class -- all vessels under 100' or all vessels under 5kts or....). As near as I can tell, no commercial app or chart plotter or AIS allows this. OpenCPN does, but it has no regulatory oversight or corporate lawyers driving design decisions.

I truly suspect that the big boys are required to have all those Class B icons cluttering their screens -- and offshore they are happy for it

So I’m actually sitting in the helmsman seat of a Deep Sea ship right now. There is a whole bunch of filtering they can do on AIS to avoid alarm fatigue and keep their situational awareness to where it needs to be. First, you have the concept of both active and sleeping AIS. On the screen it’s the difference between a small triangle (sleeping) or larger triangle, with the ship name, and speed vector. In congested waters, they’ll set the system to not auto activate class B contracts. They’ll also not activate CPA alarms on the class Bs if, say, laying at anchor.

All that said, though, they very rarely actively hide contacts. It’s more as to whether a given contact is highlighted, and whether it will generate a cpa alarm.

[chrisr]

[QUOTE=hjohnson;3742644]So I’m actually sitting in the helmsman seat of a Deep Sea ship right now. /QUOTE]

that's nice but when i was a master i would have kicked your butt all over the chartroom for playing with your phone while on watch !

of course perhaps you are not on watch in which case what are you doing on the bridge annoying the watchkeeper ?

cheers,

[IslandHopper]

[QUOTE=chrisr;3742972]

Originally Posted by hjohnson

So I’m actually sitting in the helmsman seat of a Deep Sea ship right now. /QUOTE]

that's nice but when i was a master i would have kicked your butt all over the chartroom for playing with your phone while on watch !

of course perhaps you are not on watch in which case what are you doing on the bridge annoying the watchkeeper ?

cheers,

I'm still a Master and these days it's pack your **** and find another job, on watch or not, no private phones on the bridge during operations which is pretty much 24/7/365.

Plenty of other places you can go when off watch to play with your phone instead of annoying the bridge crew.

And no, we do not filter out ANY AIS targets, period, and never been on a vessel that has.

[hjohnson]

[QUOTE=chrisr;3742972]

Originally Posted by hjohnson

So I’m actually sitting in the helmsman seat of a Deep Sea ship right now. /QUOTE]

that's nice but when i was a master i would have kicked your butt all over the chartroom for playing with your phone while on watch !

of course perhaps you are not on watch in which case what are you doing on the bridge annoying the watchkeeper ?

cheers,

I’m actually a tech for the nav system, ship was on autopilot, and I’m just waiting for an intermittent fault to crop up. So, since the ship was mid Atlantic with no traffic within 30+ miles, they don’t mind me sitting here being quiet, and want me very close in case it goes awry again. But it’s also a ship with a reasonably relaxed culture when they’re not in traffic.

Anyhow, to the original point, the ship doesn’t filter class Bs, but also doesn’t highlight them when the ecdis starts filling up with contacts.

[Jim Cate]

^^^^
Thanks for clearing things up! The order for keel-hauling is now rescinded.

Jim

[chrisr]

[QUOTE=hjohnson;3743148]

Originally Posted by chrisr

I’m actually a tech for the nav system, ship was on autopilot, and I’m just waiting for an intermittent fault to crop up. So, since the ship was mid Atlantic with no traffic within 30+ miles, they don’t mind me sitting here being quiet, and want me very close in case it goes awry again. But it’s also a ship with a reasonably relaxed culture when they’re not in traffic.

Anyhow, to the original point, the ship doesn’t filter class Bs, but also doesn’t highlight them when the ecdis starts filling up with contacts.

ok...still feels wrong, but fair enough i suppose

cheers,

[Flatswing]

Originally Posted by singlespeed

Not a lot in the undeveloped third world countries. Many vessels that are supposed to have them, simply can't afford them. Don't rely on them, especially in known drug running or smuggling corridors or waters known to have piracy issues.

I mainly cruise the AICW & Bahamas. Personal experience is at least 40% of boats we pass don’t transmit AIS & of those, 40% of sailboats haven’t programmed their boat’s information (like name etc). Frustrating because it could be so useful.

[donradcliffe]

Originally Posted by Flatswing

I mainly cruise the AICW & Bahamas. Personal experience is at least 40% of boats we pass don’t transmit AIS & of those, 40% of sailboats haven’t programmed their boat’s information (like name etc). Frustrating because it could be so useful.

If you ever bought a class B AIS in the US, you would know that you can't buy one without the Sales organization preprogramming your AIS with the name of the boat.

When you use your AIS, the first information you get for a target is the short sentence which only includes the MMSI number. However a little patience will give you the other vessel's name. If your AIS display hasn't provided the name within 7 minutes, you need an new AIS display.

[Flatswing]

Originally Posted by donradcliffe

If you ever bought a class B AIS in the US, you would know that you can't buy one without the Sales organization preprogramming your AIS with the name of the boat.

When you use your AIS, the first information you get for a target is the short sentence which only includes the MMSI number. However a little patience will give you the other vessel's name. If your AIS display hasn't provided the name within 7 minutes, you need an new AIS display.

Well the quoted reply sounds very authoritative. Unfortunately, it’s incorrect.
I bought my Vesper XB8000 here in the US from a respected marine electronics dealer. The instructions to set it up with boat name, MMSI etc. are easy to follow and were done after the (self) install to add the antenna placement parameters etc.
My MFD (Navionics) & also my iPad (Aqua Map) allow me to touch the screen to bring up the additional vessel info (saves screen clutter) I do this routinely, hence my original statement.

Perhaps there was confusion based on the obligate need to return the unit to a dealer or possibly manufacturer depending on brand to reprogram the MMSI?

[rslifkin]

Originally Posted by Flatswing

Well the quoted reply sounds very authoritative. Unfortunately, it’s incorrect.
I bought my Vesper XB8000 here in the US from a respected marine electronics dealer. The instructions to set it up with boat name, MMSI etc. are easy to follow and were done after the (self) install to add the antenna placement parameters etc.
My MFD (Navionics) & also my iPad (Aqua Map) allow me to touch the screen to bring up the additional vessel info (saves screen clutter) I do this routinely, hence my original statement.

Perhaps there was confusion based on the obligate need to return the unit to a dealer or possibly manufacturer depending on brand to reprogram the MMSI?

Legally, they shouldn't have sold it to you un programmed. It's a legal requirement for the dealer to program it in the US. Some of the parameters can be changed after, but you have to go back to a dealer for an mmsi change.

[wholybee]

Originally Posted by Flatswing

I mainly cruise the AICW & Bahamas. Personal experience is at least 40% of boats we pass don’t transmit AIS & of those, 40% of sailboats haven’t programmed their boat’s information (like name etc). Frustrating because it could be so useful.

Static information like the ships name is transmitted less frequently. It is possible that these boats have everything programmed, but you haven't received the transmission with that static data yet, only the position data.

[Captain Bill]

I don't have a story about what it does for u, but rather what not having one almost did for us. About 7 years ago a 114ft motor yacht name Andiamo was traveling north of Nassau doing 14 knots. The Idiot Captain left some unqualified morons on the bridge with instructions to call him if the AIS alarm went off. We were north of Nassau on about the same course headed for the Berrys under full sail doing about 7-8 knots. At the time I had an AIS receiver only and started getting concerned when they had a CPA of less than .1 miles at a range of about 4 miles. I tried several times to call them on the radio to no avail. I'm quite sure no one was at the helm and I ended up taking evasive action to avoid being run over from dead astern. I made a securite broadcast to alert other vessels to the fact that there was a large motor yacht named Andiamo headed towards the Berry's with no one at the helm. When they were about 4 miles past us some moron says on the radio, "are you talking about us". After I had made it clear we were, he said I'll get the captain. The captain came on a couple of minutes later and said the AIS says we missed you by 4 miles, then I told him we were not broadcasting AIS and that the actual distance was about 50 feet and the morons he left on the bridge had not seen a 60ft set of white sails going buy just 50 or so feet away. I now have broadcast AIS primarily to protect me from morons in large power vessels. I have a bit more faith in professional crews on freighter and such, but no trust at all with yacht crews.

[Flatswing]

Originally Posted by wholybee

Static information like the ships name is transmitted less frequently. It is possible that these boats have everything programmed, but you haven't received the transmission with that static data yet, only the position data.

Yes -good point. My understanding was transmission of additional info. like boat name etc. was every 2 minutes. Perhaps it's longer? I typically have the AIS targets on screen for 10+ minutes since I cruise at 7.5Kn or less. Perhaps RSLifkin is correct in that the dealers are inputting the MMSI, perhaps expecting the boat owner to add the boat name & other details later? Hailing another boat by its MMSI is pointless, I certainly don't have mine memorized.