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Old 18-05-2013, 08:04   #211
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Re: Please turn your AIS off when docked/moored/anchored

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Originally Posted by Kettlewell View Post
Yes, but if you have 50 docked boats with active AIS and 50 slow-moving boats with AIS (maybe a regatta), you now have 100 targets.

To me it is simple commonsense--there is no valid reason to leave AIS on when docked, moored, or anchored, so why cause problems for people who are actually using AIS? Even if you could care less about your fellow yachty, think of the poor commercial mariner trying to sort it all out. Is courtesy obsolete?
+1 Although I can see the benefit when at anchor in some locations, and even on the dock if you are only on it temporarily eg a fuel berth, then everybody knows it's in use. It also could be useful on public moorings so others know it's taken from further away. But to leave your boat on a mooring or marina berth unattended with it running for weeks is not good practice. I guess I am also thinking of the future, in five years time what is AIS going to look like with more and more boats fitting class A's and B's?

I like the idea of having the freedom to turn AIS off when its not needed and on when seamanship requires. I would prefer that rules are not made to regulate when I have to switch it on and when I have to switch it off. Such rules might mean that if I forget to switch it off at the end of a voyage I end up fined, or shamed, or having to travel a long way back to the boat to switch it off. And I do not want to have to use AIS every time I leave the dock or an anchorage, I like sailing to be about the sails and the wind. I like the choice

To avoid such rules we are best off using AIS responsibly, so we hopefully do not end up with marinas full of empty boats all with active AIS units, which may force the local ports authorities to start to regulate the use of AIS for pleasure boats.
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Old 18-05-2013, 08:09   #212
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I tried to read all the posts but may have missed these observations:

1) I'm willing to bet that most of the docked AIS units are left on because of the web based AIS viewers. Owners from anywhere in the world can check if their boat has moved "for free". Is this a discourteous use of AIS? Probably so but it is debatable.

2) It is possible to have so many AIS units chattering that all available time slots are used up. This has thwarted attempts to provide a global monitoring system using AIS receivers on satellites. This is a fundamental flaw in the system in my view brought on by the desire (unfounded also in my view) to use low cost TDM GMSK as the air interface instead of something (e.g. CDMA or COFDM) that could handle a lot more squawking devices. Think WiFi for example. For this reason, I agree with Evans that AIS should be turned off when docked. It might help if AIS transmitters only tried to send data very infrequently (say once per hour) when stationary for some preset long time (like one hour). As AIS becomes more popular it will require some rethinking of the standard I believe.

3) Clearly the receive software needs to be improved a lot if it gives an alarm that you are in danger of collision with a stationary vessel even though it is obvious to the most casual watch keeper that there is no chance of a collision. I am tempted to blame this one on tort law issues but it could just be we need to let the software people work through these real world problems. Only time will tell if the situation improves or not. This thread will be seen by AIS software developers I am sure.

New technology will often require revisions of best practices and Evans request is not in vain. I believe he is right and I believe he along with other respected voices ought to speak up even if the great unwashed think it in vain. After all, necessity is the mother of invention. He is only pointing out a problem and some innovative person is probably thinking up solutions right now. If so then that would be the best outcome.
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Old 18-05-2013, 08:10   #213
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Re: Please turn your AIS off when docked/moored/anchored

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To avoid such rules we are best off using AIS responsibly, so we hopefully do not end up with marinas full of empty boats all with active AIS units, which may force the local ports authorities to start to regulate the use of AIS for pleasure boats.
Exactly!

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Old 18-05-2013, 08:21   #214
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Re: Please turn your AIS off when docked/moored/anchored

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To avoid such rules we are best off using AIS responsibly, so we hopefully do not end up with marinas full of empty boats all with active AIS units, which may force the local ports authorities to start to regulate the use of AIS for pleasure boats.
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Exactly!

+1

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Old 18-05-2013, 08:22   #215
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Re: Please turn your AIS off when docked/moored/anchored

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Originally Posted by tartansail View Post
This discussion reminds me of the early days of the Web. Pre-Netscape, when Mosaic was the commonly used browser (Think Class A), there were a limited number of sites and most had so little data (or were "Under Construction") that it felt like the Web was understandable and the information manageable and accessible. Over a very short time after Netscape was released (Think Class B), the Web became an overwhelming cacophony. Over time, the tools of accessing, subscribing and filtering have made it possible for my 90 year old father to find his way around without having to cope with the petabytes of data that are available for access.

It's hard to envision that we're not going to see a similar, though more modest, explosion in AIS data transmission. Hopefully, in the same way, tools to filter and present relevant information will follow.
A perceptive comment.

It does seem to me that the problem is fundamentally in the system, and not in the way people use it.

The system should not be overwhelmed by targets, and should not require people to do particular things to prevent interference.

Sounds to me like there are too few time slots and too little processing power in the system, and not nearly sophisticated enough filtering.
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Old 18-05-2013, 08:30   #216
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Re: Please turn your AIS off when docked/moored/anchored

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Originally Posted by colemj View Post
That is too bad. I just looked back over this whole thread and for the most part found it very calm with reasoned debate. Given the potential of this topic to draw hard lines, it has been one of the most reasonable threads on this forum. There were a few minor instances of ad hominem attacks and mild nastiness, but most of those came from the OP and people struck with the OP's "fame". The others were from a single poster.

It should take much more than that to attract the attention of the moderators. Please tell me this isn't a case of "favored" members.

Should I start an anchor thread to keep you busy elsewhere?

Mark
There is no such thing as "minor instances" of ad hominem attacks and "mild" nastiness according to the forum rules. Ad hominem attacks and nastiness in all their forms are really forbidden here. Further incidents of this will result in sanctions.
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Old 18-05-2013, 08:32   #217
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Re: Please turn your AIS off when docked/moored/anchored

I think AIS filtering algorithms are going to be a big thing in the future of colregs law rule 5, and filtering settings are going to start to show up heavily in collision court cases and insurance claims. It will be interesting to see what developes, Open CPN would seem like a good place to start to play with these algorithms.

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I can also see big problems with the class B 30 second updating interval in some tight situations, especially if the system is clogging up and the intervals get stretched out to a minute or more and the target is altering course or speed.
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Old 18-05-2013, 08:36   #218
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Re: Please turn your AIS off when docked/moored/anchored

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Originally Posted by Kettlewell View Post
Exactly!

Sigh. You are missing the point again.

How about this instead? Suppose all of these actively being used vessels have AIS transponders? How is this different?

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Old 18-05-2013, 08:38   #219
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Re: Please turn your AIS off when docked/moored/anchored

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Who is "trying to make a law"? In my opinion, this is a completely inappropriate reaction. Some people are making a suggestion for a way to use AIS in a way which is more courteous and which makes it easier for other mariners to use the system. There might very well be a right or wrong way -- it's a subject for discussion. You have every right to politely disagree, and to politely state your arguments and attempt to persuade other people of your point of view. But making such a suggestion, and arguing for it, does not amount to "trying to make a law", and to suggest that is really inappropriate. ............
"really inappropriate"?

I thought this was open discussion.

The bottom line here is, some folks think everyone should do something their way and if they don't they are bad sailors or bad citizens.

Other people think the first group is wrong and they are going to do things their way and to hell with the first group. This thread can go on for a hundred pages and nothing will change. You might as well close the thread, there's nothing more to say.
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Old 18-05-2013, 08:39   #220
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Re: Please turn your AIS off when docked/moored/anchored

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Exactly!

Are you ready to admit that you would have a problem navigating that coastline if every boat in that marina was actively transmitting? Or was that simply an extreme example picked to prove a point (it is one of the largest marinas in the world).

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Old 18-05-2013, 08:47   #221
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Re: Please turn your AIS off when docked/moored/anchored

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Originally Posted by colemj View Post
Sigh. You are missing the point again.

How about this instead? Suppose all of these actively being used vessels have AIS transponders? How is this different?

Mark
Query whether these situations (also, the tight quarters situation mentioned in the previous post) are really suited to AIS in its present form. Can it give useful information? If you are getting a position update only every 30 seconds from Class B transponders -- at best! -- then by the time you're a few cables away, surely the predicted course and so forth of Class B targets starts to become fairly useless, and the alarms become pure noise. No?

Maybe it's worth thinking a bit about how we use it. I, for one (and not presuming to speak for others), don't look at it when entering a crowded harbor with dozens of vessels at close quarters. It seems to me that AIS and its calculations of collision courses is not useful at very close quarters with small vessels are being mostly hand steered. I, for one, use the Mark I eyeball in such situations and ignore the plotter.

I suspect the system is not even designed, really, for this kind of situation, and I'm not quite sure how it could be.

So maybe not just the system, but the operator also needs some adjustment.

I appreciate that there are some valid arguments in here [in this very point, I mean] for no one caring whether transponders are switched off in the berth, or not, which is not to say necessarily that they are persuasive.
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Old 18-05-2013, 08:57   #222
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Re: Please turn your AIS off when docked/moored/anchored

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"really inappropriate"?

I thought this was open discussion.

The bottom line here is, some folks think everyone should do something their way and if they don't they are bad sailors or bad citizens.

Other people think the first group is wrong and they are going to do things their way and to hell with the first group. This thread can go on for a hundred pages and nothing will change. You might as well close the thread, there's nothing more to say.
[moderator hat back on]

Here is a basic lesson in participating in online discussions:

If you are faced with someone who thinks everyone should do it their way, and say or imply that you are a bad sailor if you disagree with them, you have basically two valid choices of how to respond:

1. Just move on to the next thread, and don't get involved.

2. Ignore the implication that you are a bad sailor, and politely engage the substance of the issue. Raise the level of politeness and respectfulness of the thread, if it seems to have slipped, don't climb into the mud yourself.

What is not a valid choice -- and you might read the rules if you have any doubt -- is to engage the "you are a bad sailor" part of what was said with more of the same. If it was actually rude, by all means, report it to us. But you should keep in mind that very, very often, what seems to one person like an insult was really not intended that way. A strong argument in favor of some practice or another, might seem to some people who have a different opinion, to be an insult. So ignoring that part of what has been said is very often the most productive way to take the discussion forward.

This particular thread is very interesting and most of the discussion has been very productive. It is absolutely not true that "nothing new can be said". Whenever you find yourself thinking that, it's a good sign that you've allowed your mind to close on the issue. That's a good sign to move on to another thread -- why even read more, much less write, if you think that "nothing new can be said"?
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Old 18-05-2013, 09:08   #223
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Re: Please turn your AIS off when docked/moored/anchored

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Query whether these situations (also, the tight quarters situation mentioned in the previous post) are really suited to AIS in its present form. Can it give useful information?

Maybe it's worth thinking a bit about how we use it. I, for one (and not presuming to speak for others), don't look at it when entering a crowded harbor with dozens of vessels at close quarters. It seems to me that AIS and its calculations of collision courses is not useful at very close quarters with small vessels are being mostly hand steered. I, for one, use the Mark I eyeball in such situations and ignore the plotter.

I suspect the system is not even designed, really, for this kind of situation, and I'm not quite sure how it could be.

So maybe not just the system, but the operator also needs some adjustment.

I appreciate that there are some valid arguments in here [in this very point, I mean] for no one caring whether transponders are switched off in the berth, or not, which is not to say necessarily that they are persuasive.
Well, you just restated what several of us have been saying.

The OP's issue was navigating in a harbor with dozens of vessels in close quarters.

Operator adjustment to this situation was the point some of us were making.

Whether the system itself can handle it has had some debate, with several providing data suggesting that there is no real problem. I can't believe class B was designed from the start without thought to the possibility that more than a few boats would be using it at any given time.

But perhaps it was. In that case, with countries either mandating it or considering mandating it, I suspect that the system will be adjusted to accommodate.

Adjusting the operator will still be a requirement, though.

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Old 18-05-2013, 09:08   #224
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Re: Please turn your AIS off when docked/moored/anchored

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Sigh. You are missing the point again.
The point I am making is that if you combine the marina photo and your photos you have a worse situation than you have without all the boats transmitting in the marina. It isn't about entering the marina, it is about passing near to the marina while at the same time dealing with actual traffic you have to worry about out in the channel. There are numerous places in the world with lots of boats in marinas in a small area. I have read that there are 40,000 resident yachts in Ft. Lauderdale, and those would all be within a few miles of the inlet. OK, so you filter out the ones that aren't moving, but then that eliminates all the cruise ships hovering waiting to enter the port, or the Pilot Boat, or the marine patrol, or the boats just idling for a moment.

Maybe the answer is just an "in port function" on AIS that is triggered automatically once your boat hasn't moved for say an hour or something.
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Old 18-05-2013, 09:23   #225
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Re: Please turn your AIS off when docked/moored/anchored

I am going to be very presumptuous and attempt to get inside the OP's head.

I think the OP encountered a novel (for him) situation with his newish AIS unit and saw an easy and quick solution for his problem. He posted a seemingly innocuous and polite request for this solution to be implemented.

Others who have many years of experience operating with AIS in the situation the OP described attempted to help him. In doing so they questioned some of his newly acquired premises, and even provided some hard data in support.

That raised his hackles and he and some others became a bit heated for a while. Instead of recognizing the actual underlying issues and environment that was causing them, the OP turned it toward emotional and gut-level arguments and appeals. No data were provided - just appeals to the "common good" and "courtesy", etc. These resonated with others and also blinded them to the real issues - which were completely outside of, and divorced from, "courtesy", etc.

It was pointed out that yes, people could be more courteous and aware, but that wasn't the OP's real issues and would never solve his actual problems.

The OP then took his ball and went home because there was nothing he could do to make several of us stop seeing the underlying issues and their environments.

Mark
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