knuterikt
Well-Known Member
What happens if someone is sitting on top of it?
Which Ais Transponder/Transceiver
- Thread starter brian48
- Start date
skipmac
Well-Known Member
Well if the commercial vessel has radar (most likely) and is watching it (debatable). However, if I had to choose between only one I would pick radar instead of AIS. With radar I can see anyone around me (not to mention land, buoys and markers, etc), whether they have radar, AIS or nothing.
john_morris_uk
Well-Known Member
You mean the ones that filter out Class B targets? Like ships have?
Why perpetuate this myth? Shown time and again to be wrong. Ships are as interested as anyone in not colliding with other vessels whether it's a small leisure craft or another large ship. They experience the same problems we all do when faced with multiple targets in confined waters. We have to turn the alarm off in confined waters and perhaps ships do as well but so what? Finding an extreme case where AIS isn't very useful doesn't mean it's not a fantastic aid to collision avoidance in open waters.
True in all confined waters. On my mooring I have to turn the AIS alarm off or every boat coming up and down the river is assessed as a 'dangerous target'. See above.
I agree. We've just installed the latest plotter with their latest software and it addresses all the problems that were complained about. Dig into the options menu and there are all sorts of possibilities for choosing alarms for CPA and time to approach etc. Lots of options for how it's displayed. The default mode has any 'dangerous' targets flashing red on the display.
It's a false choice. They do different things. Both are aids to collision avoidance. Neither negate the use of eyes and compass. To complain that one or the other isn't the whole answer misses the point. Even with radar you have to look out as some targets don't paint a return until they are very close. This sometimes includes fishing boats. In nearly fifty years of sailing in the channel/uk (and this applies in most other waters as well) I can only remember a slack handful of times when a ship didn't comply with IRPCS and didn't appear to be keeping a lookout. (Don't get me started on my experiences of local ferries in the Aegean and some other parts of the Med' though!!)
To answer the OP, we have the Raymarine AIS as it integrates seamlessly with the Raymarine display we have. We are very happy with it.
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GHA
Well-Known Member
The good news is that (as we're obviously talking recievers here) you don't have to choose. If you can afford a radar then you can afford an ais reciever as well, they're cheap these days.
Handy, as they do different things.
Bru
Well-Known Member
Thread drfit! Commercial vessels filtering out class B AIS
It has indeed been established that some (if not all) commercial systems have the facility to filter out Class B targets
That doesn't mean that commercial vessels always filter out Class B targets though. Nor does it make Class B transceivers pointless
In a target rich environment such as the screenshot of the Solent it would make sense for the OOW of a large commercial vessel to declutter the AIS targets by removing the hordes of small vessels and use the Mk.1 eyeball to keep an eye on them
But imagine what would happen to the said OOW if he was ploughing along in open waters and ran down a small vessel that was transmitting AIS and he had the ship's systems configured to ignore Class B targets. He would, rightly, be deemed to have failed to use all appropriate means available to avoid a collision
I don't doubt that it happens (filtering out Class B when they shouldn't). Then again, there have been recorded and reported incidents of commercial vessels failing to properly configure their radar and/or failing to keep a proper lookout etc.. As ever, it pays to assume that the big beggar is out to get you until it's a certainty that he isn't! A Class B transceiver isn't the be all and end all of being seen by other vessels but it is a useful tool in the toolbox
It has indeed been established that some (if not all) commercial systems have the facility to filter out Class B targets
That doesn't mean that commercial vessels always filter out Class B targets though. Nor does it make Class B transceivers pointless
In a target rich environment such as the screenshot of the Solent it would make sense for the OOW of a large commercial vessel to declutter the AIS targets by removing the hordes of small vessels and use the Mk.1 eyeball to keep an eye on them
But imagine what would happen to the said OOW if he was ploughing along in open waters and ran down a small vessel that was transmitting AIS and he had the ship's systems configured to ignore Class B targets. He would, rightly, be deemed to have failed to use all appropriate means available to avoid a collision
I don't doubt that it happens (filtering out Class B when they shouldn't). Then again, there have been recorded and reported incidents of commercial vessels failing to properly configure their radar and/or failing to keep a proper lookout etc.. As ever, it pays to assume that the big beggar is out to get you until it's a certainty that he isn't! A Class B transceiver isn't the be all and end all of being seen by other vessels but it is a useful tool in the toolbox
pvb
Well-Known Member
As others have said, it's no myth, and you're the one in the wrong!
pvb
Well-Known Member
As others have said, it's no myth, and you're the one in the wrong!
john_morris_uk
Well-Known Member
No need to say it twice!
My apologies, although the debate quoted shows there's some confusion.
Perhaps my real issue is that I'm not convinced about the paranoia that is exhibited over large vessels and the cry of 'they can turn off Class B is another example of the paranoia shown by some.
The main purpose seems to be to stop the plethora of multiple alarms when one is in confined waters. I freely admit that I have taken to turning off the AIS alarm when approaching a harbour.
AIS is an aid and no one is suggesting that it guarantees other vessels will see you and comply with IRPCS. However to criticise it because one system can filter targets out (perhaps quite reasonably and to avoid a cluttered display and confusion in confined waters) and we then assume that bridge watchkeeper safe so incompetent that they routinely forget to reset the system seems a little OTT.
Everyone has a duty to use all available means. I still believe Class B is a good thing.
BrianH
Well-Known Member
Hardly confusion, more belief suspension by one professional mariner who had problems accepting it despite the functionality being clearly stated within the Furuno manuals and confirmed by a Furuno representative in the Panbo article cited. It is perhaps significant that he did not follow up to provide any evidence to support his "confusion" despite an assertion to research the matter.
Of course "Class B is a good thing", few would now dispute that, least of all I who installed a receiver in 2007 and upgraded to a transponder in 2014. However, my strategy is to never assume that my AIS signal is being viewed on all bridge decks but I consider it a valuable aid, nevertheless.
Given that assumption what benefit did the upgrade to a class B transponder bring to your sailing?
I assume you do not venture out of the Solent these days?
skipmac
Well-Known Member
The good news is that (as we're obviously talking recievers here) you don't have to choose. If you can afford a radar then you can afford an ais reciever as well, they're cheap these days.
Handy, as they do different things.
In my case definitely not talking receivers. If (or when) I ad AIS it will be a transceiver.
BrianH
Well-Known Member
That, despite my overly cautious assumption and preparedness to make a defensive manoeuvre, commercial ships appear to change course to avoid me well in advance, more often than when I didn't have a transponder. All an assumption, of course.
pandroid
Well-Known Member
Can someone confirm that the Em-track 100 works properly with the latest litehouse software? I'd prefer this unit to the raymarine ais
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pvb
Well-Known Member
I only posted once; the wonderful forum software obviously decided it was worth repeating.
john_morris_uk
Well-Known Member
Out of interest, why?
FullCircle
Well-Known Member
FullCircle
Well-Known Member
I have now bought a Vesper XB8000 on the strength of this (and others) thread. Looking forward to the WiFi capability to the Netbook/OpenCpn.
Also bought the Vesper splitter as it has a separate input for the AM/FM radio as well as the VHF, with some tricky gubbins to halt AIS during VHF transmissions.
Also bought the Vesper splitter as it has a separate input for the AM/FM radio as well as the VHF, with some tricky gubbins to halt AIS during VHF transmissions.
knuterikt
Well-Known Member
it works fine with my i70 displays and Furuno nn3d plotter.
I don't know if Raymarine have implemented any specific non standard features in lighthouse.
I have installed a switch to turn of transmit
