Class B AIS waste of money

[TheThunderbird]

Are those AIS getting so hot an issue!?

[Paul Elliott]

Look, my point is that we shouldn't make fun of someone for calling it an AIS Transponder, when that exact term is being used by the Coast Guard, the IMO, and half a dozen other regulatory and standards bodies. You may disagree with the term, but using it is hardly a sign of ignorance.

[Littlechay]

Originally Posted by Paul Elliott

You may disagree with the term, but using it is hardly a sign of ignorance.

What provoked the responses in this case was the OP giving us his/her string of (not very impressive) qualifications and the amount of words pouring from his/her keyboard. Normally I'd let transponder/transceiver ride.

[Exile]

Originally Posted by Littlechay

Normally I'd let transponder/transceiver ride.

Understandable that you normally would, since just about every major mfg. & vendor of AIS devices also describe their units that transmit and receive AIS information as transponders.

https://www2.vespermarine.com
Comar Systems manufacturers of products for the marine Automatic Identification System (AIS) market
CLASS B AIS TRANSPONDER FA-50 | AIS | Products | FURUNO
Digital Yacht - AIS Transponders
MA-500TR Class B AIS Transponder - Features - Icom America
AIS Transponders

As for the OP, his obvious errors were quickly and quite throughly corrected, so not sure why his posts need to continue to be picked apart and his credentials repeatedly thrashed.

[Littlechay]

Originally Posted by Exile

Understandable that you normally would, since just about every major mfg. & vendor of AIS devices also describe their units that transmit and receive AIS information as transponders. [/url]

As for the OP, his obvious errors were quickly and quite throughly corrected, so not sure why his posts need to continue to be picked apart and his credentials repeatedly thrashed.

See above - widespread use doesn't make it correct. However I am a lifelong electronics/communications engineer and I do know the difference - even if those that wrote the documents you quote don't.

Not sure why correcting transponder has to be repeatedly thrashed either.

[tanglewood]

When you consider all the perceived clutter and nuisance cased by all the boats with Class B AIS, consider what the situation would be if all those same boats had Class A AIS. We would have exactly and precisely the same clutter issue that exists today. So it really has nothing to do with Class B, but only with the proliferation of AIS.

Also regarding filtering, every device I've worked with allows for filtering out targets that are moving less than some threshold speed. To me that's a sensible and useful filter if you want to remove icons from your screen. It completely nullifies any argument about moored boats still transmitting AIS.

Filtering based on Class B vs A is arbitrary. You might as well filter out boats with blue hulls, or boats with Rocna anchors.

[Exile]

Originally Posted by Littlechay

See above - widespread use doesn't make it correct. However I am a lifelong electronics/communications engineer and I do know the difference - even if those that wrote the documents you quote don't.

Not sure why correcting transponder has to be repeatedly thrashed either.

Well, I certainly appreciate this helpful thread confirming for me that Class B AIS is not a waste of money, the various reasons why sailors may not turn off their AIS transceivers, and/or their AIS transponders, when they leave their boats, and maybe even why it might not be the best idea to, in your words, "stuff" the Colregs. Thanks for all the input.

[Paul Elliott]

Originally Posted by Littlechay

See above - widespread use doesn't make it correct. However I am a lifelong electronics/communications engineer and I do know the difference - even if those that wrote the documents you quote don't.

Not sure why correcting transponder has to be repeatedly thrashed either.

We are arguing because we enjoy it. Would you care to comment on AIS Message #15 (see my post http://www.cruisersforum.com/forums/...ml#post2294081), and give us your opinion as to why this doesn't meet the criteria for being a transponder?

[transmitterdan]

Originally Posted by CarinaPDX

A DSC radio responds to a position request; AIS does not. AIS repeatedly broadcasts the position, un-requested.

Greg

The AIS standard has messages for requesting units to transmit their position message on demand instead of waiting for a time slot. Each unit is supposed to indicate whether it will respond to these messages or not. I think all class A units are required to have this feature. I think class B units may or may not have the capability. So it would seem that the term transponder is at least sometimes the correct terminology

[Littlechay]

Originally Posted by Paul Elliott

We are arguing because we enjoy it. Would you care to comment on AIS Message #15 (see my post http://www.cruisersforum.com/forums/...ml#post2294081), and give us your opinion as to why this doesn't meet the criteria for being a transponder?

See my post #102 and TxDan's above. Most class B, maybe all, are not transponders in any sense.

[sailjumanji]

Originally Posted by SV Enough

I'm hoping to prompt some discussion on what a total waste of money purchasing and installing a class B transponder on your please craft is.

Here we go again. Let me guess - you don't have AIS? And you are either trying to justify that decision, or label others as money wasting idiots?

I have a Vesper XB8000 transponder (their term). I find it invaluable to use when traveling on the ICW, dealing with passing protocol. It beats the crap out of the old way of not knowing who was coming, and having to guess their name, know exactly what mile marker you are on to reference when hailing them over the VHF, etc. Now I see them on the chartplotter, hail them by name, agree on passing 1 or 2, and done. They know my intention, I know theirs.

In open water, its also nice to know whether I am on-course to collide with a cruise ship (yep, off Bimini), or any other collision paths with commercial vessels - especially at night. And have been hailed by ships in those situations as well, so I guess they all don't turn them off.

My only regret was not buying one sooner. And yeah, I have a 4G radar that I like as well. Just wasting my money like crazy!

[Sailshabby]

Originally Posted by SV Enough

I'm hoping to prompt some discussion on what a total waste of money purchasing and installing a class B transponder on your please craft is.

If your objective is is "be seen by commercial traffic", forget it! I personally have been summoned to the bridge to SPECIFICALLY check Furuno/ECDIS radar settings and ensure that "except class B" is ON, meaning exclude them. For proof see

Class B AIS - Filtering Of Targets By Ships – gCaptain

Mark Fay,
Merchant Marine Credential Jr. Engineer, QMED, AS-E / MSC ET

Disturbing to hear from a "Credential (sic) Jr. Engineer." See you out on the water - maybe...

[CarinaPDX]

Good grief. I will stand with my conclusion that AIS is not fundamentally a transponder technology. The ability to respond to requests, on an exception basis, doesn't alter that.

I suspect the choice of the word "transponder" was intentionally misleading by the proponents of AIS. Partly it was using the known concept of a radar transponder to explain it, and partly it was a way to draw attention from the truth: all ships would be constantly sending out their positions (not to mention cargo and destination) in plain text for all to see. So it was a means of getting acceptance without raising uncomfortable facts - just like our politicians.

I'll use the technically more accurate description: transceiver.

Greg

[StuM]

Looks like the troll succeeded, he's got us arguing with each other.

[weavis]

Originally Posted by StuM

Looks like the troll succeeded, he's got us arguing with each other.

Stu, people just open the door. The choice to walk through is entirely a personal one. Better to state an opinion rationally, and stand on a validated point than slug it out toe to toe. It results in disparagement of each other rather than the subject in hand.

Life and death it aint...