The Other Side of AIS...this deserves a thread of its own

[NOHOH]

If a fool persists in his folly, he will become wise. W. Blake

This is preposterous bluster and even more insulting. Why on earth would I be using a cheap, seven year old Taiwan receive-only component that has not even been upgraded to modern standards such as the full addition of Class B protocols, if I had vested interests?


This is truly bizarre, words fail me - and they are not words of apology.

For the first time ever on these fora, I have found someone to put on my Ignore List <Plonk>.

Hi Barnac1le...just knew you couldn`t resist looking

...if its so wonderful, why ARE you using a cheap seven year old Taiwan (whats wrong with Taiwanese stuff?) receive only component that has not been upgraded to modern standards such as the full addition of class B protocols ?

...and you still didn`t answer my basic question.


...and if ignoring people and ideas that you don`t like is your response, then you`ll never learn anything will you

 

[NOHOH]

Small Boats

Unless things have changed, radar with MARPA used to require a gyro rather than a fluxgate to enable it to fix on to the target. Usually 50% of sweeps. Is that the case with yours? Gyros are relatively expensive.

2. Radar may not see smaller targets. A small fast boat can still do a lot of damage in a collision (even though they are meant to reduce speed in fog, many do not), possibly more than a ship.

So there are two things in addition to MMSI details where rdar is not as good as AIS. Having said that in an ideal world the combination of the two systems would be best.

On the plus side for radar, it can see those larger vessels which do not have AIS switched on.

I did upgrade my compass and it did improve MARPA ability to latch onto a target and display much more consistent and accurate target information. This upgrade cost less than buying an AIS.

Small fast boats in fog would always be a menace no matter which system was being used to detect them...especially with their ability to change course quickly and often...which would probably outsmart both MARPA and AIS......though there is also the factor that they have just as much a vested interest in avoiding you too.....I feel that whilst its unlikely, though not impossible that a small (how small is small) boat will be transmitting AIS, I think I would put my money on Radar/MARPA in that situation.

Though I conceed there is no ideal solution to some situations

 

[NOHOH]

I think this thread has just about run its course

.....and I offer this information only as further background reading for those interested in the subject....

http://www.nautinst.org/ais/techFeedback.htm

 

[Conachair]

.....and I offer this information only as further background reading for those interested in the subject....

http://www.nautinst.org/ais/techFeedback.htm

and while googling merrily away don't forget to put radar assisted collision in there as well.

 

[NOHOH]

and while googling merrily away don't forget to put radar assisted collision in there as well.

This thread is NOT ABOUT radar assisted collision....if you want one of those...start it yourself

 

[Conachair]

This thread is NOT ABOUT radar assisted collision....if you want one of those...start it yourself

If you nip out into the real world for a moment you'll witness that internet forum threads do what they please, if you want editorial control then try blogging.
You were banging on before about how radar does everything you need, well it isn't perfect either, is it? Nothing is perfect, radar has strengths and weaknesses, ais the same. If you insist in putting them head to head then overall taking into account cost, current draw and other factors i think ais has the edge.
I have both.

 

[NOHOH]

RIP

If you nip out into the real world for a moment you'll witness that internet forum threads do what they please, if you want editorial control then try blogging.
You were banging on before about how radar does everything you need, well it isn't perfect either, is it? Nothing is perfect, radar has strengths and weaknesses, ais the same. If you insist in putting them head to head then overall taking into account cost, current draw and other factors i think ais has the edge.
I have both.

What I have witnessed on internet forum threads is a small number of people who behave in an aggressive and tedious manner repeating themselves over and over, alongside those who are thoughtful and courteous and have something interesting to say. Now, which category , I wonder, suits you best.

Thankyou, Sir, for breathing new life into this thread, it was beginnig to die....and I was prepared to let it go peacefully...I suggest you do the same

 

[webcraft]

Reasons to be cheerful

.
1/ Our boat is realistically too small to carry radar.

2/ We can't afford radar anyway.

3/ We don't have the battery capacity ro run radar anyway anyway.

4/ Fog has scared me more than anything, particularly running down the Portuguese coast in thick fog and when crossing shipping lanes in Biscay in poor visibility.

5/ I know ships find us hard to see on radar when the wave height gets over about 3m. I also know that ships only answer when you call them up if you call them up by name.

6/ Our NASA AIS engine was cheap as chips - £140 including a VHF aerial - and interfaces with the netbook we use as a chartplotter with OpenCPN.

7/ It has been very useful and reassuring, works like a charm. I don't know anyone who has fitted AIS who has been anything other than delighted with it.

8/ Nothing would induce me to cross Biscay, the North Sea or the Channel without it now.

9/ There has never been any suggestion that it could become compulsory for leisure craft to carry transponders, nor is there any logical reason for thinking this might happen.

10/ The OP appears to - by his own admission - have no practical knowledge of the technology in a yachting context and we must presume that he is - like a few on here - is just another agressive poster out to annoy people. He has been sussed.

- W

 

[Joker]

a small number of people who behave in an aggressive and tedious manner repeating themselves over and over

Oh, you mean, like the original poster?

 

[NOHOH]

I wondered how long it would be

......before you ladies would be back to try and settle old scores....
Again......Thankyou for breathing new life into this thread

 

[Conachair]

... there's always life left in a thread..... So ignoring the shouting ..

MARPA - never used it and don't know much about it - is it worth the outlay?
how much?
i love a gadget but doubtful,

my experience is...

The big boys transmit ais, with a cheap reciever you can see quickly if you are going to end up in the same bit of ocean. Well worth the cash for that alone.

The smaller ones especially fishing boats it really doesn't matter that much if they are transmitting ais or not, same goes for marpa, they do weird things and should always be watched, can't be trusted.

Though since I've been back in these waters there seem to be quite a lot of fishing boats transmitting and their sog is useful to know, if it's dead slow then they probably have nets down.

As for transmitting AIS, each to thier own, my boat is steel, offshore I've watched on ais the big boys alter course by 10degs about 5 miles away to miss me then go back on course.
Doubt if i would go for ais transmitter.
You're on your own out there.

 

[NOHOH]

The Final Picture

Hello Conachair
We found MARPA as a by-product of having a radar...which, as is the norm these days, is considered as a by-product to having a chart-plotter. In for a penny.....in for a couple of thousands...though there was a very small window of opportunity when the £/$ rate went to over 2 ...about 5 years ago ..and the prices went through the floor....and suddenly it was affordable....but I guess it must be considered an expensive option these days. We subsequently upgraded the electronic compass to make the MARPA work better.
I did say, about 30 posts back that having AIS was better than having nothing at all in the way of electronic aids and I do still stand by that. It has always been the `incompleteness` of the information (in the sense that not everything is transmitting)that has caused me misgivings......but in all honesty I can forsee a time when I will have an AIS reciever for use as an emergency backup system attached to a laptop...entirely separate from the boats power supply.
As to the other `issues` of privacy, freedom , monitoring and control....well they are a bigger picture and sometimes they bother me more than at others...and.....well...nothing will be resolved by discussing them here...so I wont.

I really do think this thread has run out of steam now as far as I`m concerned , so I`ll be happy to let it go.......

 

[Dockhead]

--------------------------------------------------------------------------------

Quote:
Originally Posted by maxi77
AIS is certainly not a con, yes many small craft including ours do not transmit, and yes most rocks don't transmit either, but for those vessels that do the info is very usefull, and helps in sensible descision making. It is certainly not a replacement for radar, but neither is radar a substitiute for AIS. It is another tool and a potentially useful one too.<End of Quote>

AIS can be seen as the very thin end of a very long wedge.... It is being `soft sold`to yachties as "the info is very usefull, and helps in sensible descision making." "It is another tool and a potentially useful one too."....

How long do you think it will be before the scheme is extended to include first SOLAS vessels (45`and over) and then all yachts?
How long before somebody says "well the system will only work properly if every vessel is included"....and how long before somebody comes up with the bright idea ...for example..."only vessels transmitting AIS can cross a TSS"....and then somebody will decide, after looking at your track that you were not quite close enough (70, 80, 85, 89?) to the required 90 degrees and the computer sends out the penalty notice to the vessel`s registered address....or...more topically, how long before somebody says "you were anchored in a Marine Conservation Area"....and issues a penalty notice.

AIS is essentially a mechanism for Monitoring and Control and the best way to get people to accept restrictions is to "educate" them into some of the benefits that such a system can bring..but without mentioning any possible `disbenefits`..until AFTER the system is fully up and running. ..for example seat belts in cars were voluntary to begin with, so were crash helmets on motorbikes..just as lifejackets are on boats at present.

Don`t get me wrong... I don`t think..er... Ihope..I`m not so paranoid as to think that there should be NO monitoring and control of the seas......but we are in danger of being taken in by the `soft sell` (aided by the complicit equipment manufacturers and distributors)of AIS to us boaters...and effectively `sleepwalking` into accepting a potentially very wide ranging and Orwellian state of affairs that we really WILL NOT like.

AIS in cars will be next (if its not there in some form already)

I will have AIS in my vessel as soon as I can afforrd it. It will have a switch in case for whatever unlikely reason I don't want to be tracked. Problem solved.

 

[ColinR]

.
1/ Our boat is realistically too small to carry radar.

2/ We can't afford radar anyway.

3/ We don't have the battery capacity ro run radar anyway anyway.

4/ Fog has scared me more than anything, particularly running down the Portuguese coast in thick fog and when crossing shipping lanes in Biscay in poor visibility.

5/ I know ships find us hard to see on radar when the wave height gets over about 3m. I also know that ships only answer when you call them up if you call them up by name.

6/ Our NASA AIS engine was cheap as chips - £140 including a VHF aerial - and interfaces with the netbook we use as a chartplotter with OpenCPN.

7/ It has been very useful and reassuring, works like a charm. I don't know anyone who has fitted AIS who has been anything other than delighted with it.

8/ Nothing would induce me to cross Biscay, the North Sea or the Channel without it now.

9/ There has never been any suggestion that it could become compulsory for leisure craft to carry transponders, nor is there any logical reason for thinking this might happen.

10/ The OP appears to - by his own admission - have no practical knowledge of the technology in a yachting context and we must presume that he is - like a few on here - is just another agressive poster out to annoy people. He has been sussed.

- W

well said! of course only bigger vessels transmit AIS, but in a sea its not easy to reliably pick out small vessels on radar especially yachts so an AIS reciever is good value for the money and small current draw.

 

[Seajet]

I'd just point out, I never thought I'd have radar, until a nasty experience when my single battery and steering compass failed in fog.

I've been in fog in the Channel which was far too entertaining, but do-able, being without electrics or compass ( apart from hand bearing ) in the Solent was beyond a joke.

I have an Anderson 22 which I'd already fitted with a Raytheon colour plotter, 30watt solar panel and charging coil on the 5hp outboard, usually in it's cockpit well if fog is around.

After this I fitted a JRC 12" radar, which while it takes getting used to is a real boon in bad vis'.

The radar can be run in short bursts ( unlike earlier sets which had to warm up ) allowing an eye to be kept on traffic etc.

As for AIS, I don't want to fuel the debate but I might have a reciever some time, a transmitter is unlikely.

Personally I don't fancy the cheaper AIS kits for small boats, the small monochrome display looks pretty useless to me.

 

[LadyInBed]

Anderson 22 which I'd already fitted with a Raytheon colour plotter, . . .
Personally I don't fancy the cheaper AIS kits for small boats, the small monochrome display looks pretty useless to me.

With a Raytheon colour (I assume chart) plotter you don't need a separate AIS screen, the output of the AIS engine is fed into the chartplotter.
But with any AIS unit, it isn't the picture that is important, it is the words!

 

[Lucky Duck]

I will have AIS in my vessel as soon as I can afforrd it. It will have a switch in case for whatever unlikely reason I don't want to be tracked. Problem solved.

AIS is useful either to augment a radar equipped boat or as aid to collision aviodance for those which don't have the money, battery capacity, etc to install one. Radar has limitations and for AIS it is that you are reliant other boats transmitting the correct information and you need to be aware that vessels below the mandated tonnage probably won't be visible to an AIS system. Especially if they are going to switch off their transmitters when it suits them.

IIRC a lot of the early scepticism in the forums stemed from NASA's marketing of AIS as 'radar' which it is obviously not.