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Old 18-05-2013, 22:43   #301
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Re: Please turn your AIS off when docked/moored/anchored

My couch captain understanding is AIS is used to identify boats.
When docked, it is still identification/location information. I don't want to run into a docked boat just the same as one moving.
It should not be turned off.
If the system itself can't handle a large amount of traffic/boats, the system/technology is broken and needs fixed/different implementation/protocol.
Asking boaters to turn it off is not the solution.
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Old 19-05-2013, 00:01   #302
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Re: Please turn your AIS off when docked/moored/anchored

Using AIS to avoid collision with boats tied to docks might indeed be a good idea, for someone whose idea of collision avoidance extended broadly enough, if their watchkeeping involved sitting below with the 'curtains' drawn (on a padded 'couch' surrounded by screens, and bowls of grapes) and if bandwidth were an infinite resource, like, say, crude oil <GRIN>

If you were a proper couch captain rather than a self-styled one, <re-GRIN> you might well identify with that famous couch captain from the USN who apocryphally called up a lighthouse, insisting that it change course to avoid a collision...

Where I come from, we save collision avoidance, as a term and a concept, for things whose position is unpredictable or unexpected. And I for one would prefer it to stay that way.
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Old 19-05-2013, 00:02   #303
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Re: Please turn your AIS off when docked/moored/anchored

I think someone floated the idea that Google disproves the pre-existing belief that filtering was not a viable way of extracting very small amounts of worthwhile information from very large amounts of rubbish. It used to be an axiom that Garbage In > Garbage Out.

I'm the first to say I'm astonished how well Google has managed, so far, to extract silk purses out of a bottomless pit of sows' ears, but I think it is far too soon to say that is sustainable. The size of the pit is expanding exponentially, at a doubling period which is significantly shorter than that of the worthwhile component, and only an economist or a mad hatter could portray that as sustainable.

I don't have first-hand knowledge of whether it is effectively true that Google has enough RAM for the entire www, but it must be roughly proportionate, and Moore's law is reaching the critical twenty to thirty doubling zone, around which point exponential growth starts to go cancerous.

We've been sailing with a technological tailwind in the last decade or two, much as fossil fuels gave us a once-only, never to be repeated economic tailwind throughout the twentieth century.

To assume that the past is a reliable guide to the future, in instances like this (which are 'projects' rather than 'processes'), would be to fall into the trap of those Pacific Islanders who assumed that cargo planes would continue to land and disgorge unlimited supplies after WWII ended.
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Old 19-05-2013, 00:30   #304
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Re: Please turn your AIS off when docked/moored/anchored

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Originally Posted by goboatingnow View Post
Very admirable it is too , Evans, however large groups of society, including cruisers , don't see it that way , therefor " appealing" to them is tilting at windmills. A more practical solution has to be found and that's involves you adjusting your behaviour ( or equipment /settings/filters) etc to achieve an outcome that helps you with the problem,

Not to mention that pare numbers of sailors do not identify with the " cruising community "

Dave
I think that you're unwittingly setting out a false dichotomy.

Evans does not have to win everybody over for his appeal to be worthwhile.

If he hypothetically wins a few (which he has ... and that's not counting impressionable lurkers, who have more sense than to be sniped at on this thread), and they each win a few (which seems entirely possible), the tide could turn and an appreciable difference could eventually be made.

Your reasoning implies that an appeal to a sense of community is wasted unless everyone buys it.

The only scenario where that would be true would be where those who were disposed to buy it talked themselves out of doing so by reasoning that "not everyone will, so I put myself at a disadvantage if I do"

And, yes, you could argue that group is almost as solipsistic as the first group. And more hyprocritical. What they are engaging in is a 'race to the bottom', justifying their own behaviour by making assumptions of worse behaviour by unspecified others.

Are you saying that virtually everyone you know falls into one of those two groups?

If so, please stop the planet, I want to get off.
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Old 19-05-2013, 03:06   #305
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Re: Please turn your AIS off when docked/moored/anchored

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I'm the first to say I'm astonished how well Google has managed, so far, to extract silk purses out of a bottomless pit of sows' ears, but I think it is far too soon to say that is sustainable.
There is also a very modern, very large 'public commons' experiment today that we all use, where the tension between community and selfish individuals are very apparent . . . . Wikipedia. There are definitely 'bad actors', and definitely a community trying to build a structure that is resilient to those bad actors. It's an interesting experiment to watch play out.

I studied commons in both my math/game theory and business/economics degrees. It is modeled as an 'N person with communication prisoner's
dilemma
". There is a tension/balance between on the one hand peer pressure and trust and on the other selfishness and greed, and there are balances/structures that successfully maintain the commons and others that allow it to be broken by the selfish individuals. In many team activities (sports, military, business, etc) if you take two identical teams, a selfish one will systematically loose to a selfless one; but in some activities the selfish team will beat the selfless one. I have also worked in Scandinavia, where the perspective and balance between individual and community is sustainably (over lets say a 100 years) very different than in the USA. So, it's not simple to say when a commons will work and when it will not . . . . except that historically, over a long time period (lets say +1000 years), nothing is 'forever', no culture or community survives forever.

I personally think a sad thing about modern western culture is that in leading sectors (many of my peers in wall street and CEO's) the 'peer pressure' has been turned around to reinforce selfishness rather than reinforcing community. Many of my peers truly believe that 'greed is good', even after the wall street melt down and Enron, and MCI, etc.

Anyway, while this is in fact related to AIS, it is also coming close to discussing 'politics', which we try not to do here.
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Old 19-05-2013, 03:31   #306
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Re: Please turn your AIS off when docked/moored/anchored

Well, since wikipedia has been mentioned...

Tragedy of the commons - Wikipedia, the free encyclopedia

I was one of those CEOs. And you're misunderstood yet another facet of the Tragedy.

I'm starting to wonder if you did so deliberately, or if you simply read what you were looking for, rather than what was written.

Even a quick glance at the wikipedia page, as shallow as it is, will show that the Tragedy is not a new concept. It has been discussed, dissected, critiqued, taught, and slobbered over for centuries.

It simply does not support your request. I suggest you fall back on a personal appeal-- there may be some people here who will still listen to that.
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Old 19-05-2013, 03:53   #307
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Re: Please turn your AIS off when docked/moored/anchored

My Miltech AIS has the ability to easily switch the transmitter on or off by hitting one button. But, there may be other reasons for leaving the transmitter on such as security being able to monitor your boats position in case somebody decides to steal it. As some may recall a nice Swan was stolen out of a marina in California earlier this year. I usually shut the AIS transmitter down when at anchor but, I like to leave the receive section on if only to watch the traffic and identify the ships and boats passing by. Turning off the AIS transmitter also saves power and that's a good thing too. Though I do believe when the boat is not moving it also does not transmit it's AIS identifier as often as when underway too.
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Old 19-05-2013, 04:22   #308
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pirate Re: Please turn your AIS off when docked/moored/anchored

Speaking as a non-star struck seaman... seems to me Evans has somehow forgotten his years of non-assisted sailing and become infected with the modern malaise... over use/reliance on electrical devices to do his basic seamanship in crowded waterways for him.. kinda like talkative crew who keep freaking you out with useless info that you've assessed and discounted...
I'm just hoping he's not hit the next stage yet... sitting below with a remote staring at a screen...
I keep seeing owners staring at screens for ages... makes me wonder what they can see that a 5sec glance does not tell me...
Are they waiting for the commercials...?
As for the photo's of the boats in the marina and the thought that AIS alarms somehow makes navigation difficult is laughable..
Go back to paper and eyeballs and suddenly its easy again...
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Old 19-05-2013, 04:51   #309
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Re: Please turn your AIS off when docked/moored/anchored

Following on the Internet analogy, if we're at the early stages of broad-based AIS use, we should anticipate log growth of targets over the next five years. While I am sympathetic to Evans's desire to have us model improved community behavior, at best, those behaviors will have a geometric impact (i.e. a percentage of those using AIS perform according to the community norm.) If we see a 100-fold increase in Class B transmissions (not unrealistic) and there is a 90% adherence to the shut it off when not in use request (highly optimistic), that is still a 10X increase in targets to deal with.

Which gets back to filtering and software. So, Jedi, what is your filtering software? Can it work off a Class B data? What are the platform requirements? Can I use it with iNavX?
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Old 19-05-2013, 04:57   #310
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Re: Please turn your AIS off when docked/moored/anchored

But Boatman, as a previous poster pointed out on this thread, all of the experienced cruisers are agreeing with Evans and the ones without much experience are the ones that have been disagreeing. So you do not have enough experience.

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Old 19-05-2013, 05:08   #311
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Re: Please turn your AIS off when docked/moored/anchored

Quote:
Originally Posted by s/v Jedi View Post
I am very disappointed with the AIS knowledge demonstrated here on CF. People who know a bit about it are incapable of communicating that in an understandable way to the rest and I just can't seem to accept that. I am not a native English speaker but others are and don't get much further than me.

So I'm gonna try a WAKE UP call. Here's picture of my AIS screen aboard Jedi as it was in January 2008, which is more than 5 years ago:

All of that is class-A targets, as am I there in the middle. Check out the range rings and the number of targets in front of me. I am doing 7.7 knots over ground and am monitoring two ships (right side of screen), the AS Pegasus and the TELO. You see square corners drawn around them on the plotter. You can also see the Pegasus is turning to port at 3.6 degrees/minute. She is doing 18.3 knots over ground and turning into me so making me nervous.

Now check out the alarms which are indicated by red colored ships instead of green: NONE. NO ALARMS. January 2008. Are alarms active? you bet! Now check that red area off my port bow. When I go there, I will get alarms. Let that sink in.

It's pure nonsense to state that advanced filtering software does not exist. You just don't know it's there and you didn't buy it. I did, no problems for me.

p.s. check the buttons on the bottom, incl. the SoG > 0.3 knots, the class-A only etc. Also confirm the number of targets: 147

Here's the picture as I just emerge out of this rats nest of big Panamax ships: still no alarm! (and Pegasus already anchored, see it how fast the commercial guys are!?)


Everybody can have this: it works with all AIS receivers and transponders. Just a little piece of software.
Unfortunately it looks like Y-tronic have stopped selling this software. The unregistered download only works just long enough to get a quick feel for how the PAD (predicted area of danger... The red bit) works, At a quick glance it looks like its the same as how they worked on ARPA's.

There is nothing terribly advanced about PAD's, we used to work them out on paper plotting sheets, Sperry came up with the concept along time ago for their ARPA units and then dropped it. As far as I know it doesn't take into account anything more sophisticated than any preset CPA limits. Drop the CPA limit and the PAD gets smaller, raise it and it gets bigger. It applies the same to all vessels, even ones that are no danger and are moving away, but may be currently inside your CPA limit.
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Old 19-05-2013, 05:15   #312
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Quote:
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Following on the Internet analogy, if we're at the early stages of broad-based AIS use, we should anticipate log growth of targets over the next five years. While I am sympathetic to Evans's desire to have us model improved community behavior, at best, those behaviors will have a geometric impact (i.e. a percentage of those using AIS perform according to the community norm.) If we see a 100-fold increase in Class B transmissions (not unrealistic) and there is a 90% adherence to the shut it off when not in use request (highly optimistic), that is still a 10X increase in targets to deal with.

Which gets back to filtering and software. So, Jedi, what is your filtering software? Can it work off a Class B data? What are the platform requirements? Can I use it with iNavX?
This is why Evans appeal is actually pointless. The issue is not the commons or its tragedy , its the huge herds of sheep suddenly appearing . Appealing to the sheep herders is useless as you drown in sheep.

The solution is as nick laid out. AIS is new to recreational Boaters , hence we have poor integration and tendency towards standalone devices. Integrate AIS into chartplotters , improve the display software , ensure all screens are visible to the helms person etc. we move away from the concept of some black box down below beeping at you. Your brain is infinitely better then software filters.

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Old 19-05-2013, 05:18   #313
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Quote:
Originally Posted by tartansail View Post
Following on the Internet analogy, if we're at the early stages of broad-based AIS use, we should anticipate log growth of targets over the next five years. While I am sympathetic to Evans's desire to have us model improved community behavior, at best, those behaviors will have a geometric impact (i.e. a percentage of those using AIS perform according to the community norm.) If we see a 100-fold increase in Class B transmissions (not unrealistic) and there is a 90% adherence to the shut it off when not in use request (highly optimistic), that is still a 10X increase in targets to deal with.

Which gets back to filtering and software. So, Jedi, what is your filtering software? Can it work off a Class B data? What are the platform requirements? Can I use it with iNavX?
It was called YachtAIS but the author stopped selling it last year. I think Vesper comes very close to it though, if you are willing to tune it's filters. Vesper even sells a display unit with software that you can connect to most or all AIS units.

When I started using AIS, I went to the extreme with optimizing it's features but later on I toned it down again. I now look at targets on my chart plotter and radar screens (love Furuno 3D radar with both AIS and ARPA targets.. which will merge into one in the future) and also use MaxSea TimeZero software which I like a lot. None of that is as advanced as the software I used before.

I know Vesper is reading all this and hope they will continue where Yacht-AIS left the arena. This is one area where competance can result in world leadership for AIS units. Class-A next please

About that class-A vs class-B: Evans remarked that I advised him a class-A unit. The reason for that was that he was bothered by his class-B unit skipping transmissions because of other AIS traffic. I explained that this was not a problem but just the way it is designed on purpose. Think of class-B as using the left-overs from class-A. Then, within class-B it is much like throwing some coins into a crowd of kids: whoever grabs the coins gets the coins. I compare Evans request with telling some of the kids to go away in order to get more chance for coins yourself.

For class-A units, you get assigned your transmission slots and are assured of transmissions. The transmissions are also more powerful to assure they don't go lost in channel noise.

I know it might not sound nice when I say things like class-B gets the scraps but it is, what it is, and I call it by name.
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Old 19-05-2013, 05:28   #314
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Re: Please turn your AIS off when docked/moored/anchored

Why are some people continually painting those who have not agreed that docked AIS is the problem as greedy, not courteous, etc? No one on this thread has really argued the need for AIS at a dock, and most of us agree that it is good to turn them off.

Those not on Evans "side" are simply saying that the OP problem was not a general problem of docked AIS, but a broader problem of many AIS targets - docked or not. This problem is here and getting greater. And has nothing to do with docked AIS.

When we try to explain our position, we are continually dragged down into the mud of "tragedy of the commons", morality and courtesy, where the "high road" is those who won't understand the real issue, or are incredulous because some of us disagree with a "famous" person, and the "bad" people are those who do not simply think if all docked AIS were off the problem is solved.

Can we leave the morality and all that aside in this? You can argue that leaving your AIS on at the dock is equivalent to knifing baby ducks all you want and I have every right to refuse to draw the line there, but it has nothing at all to do with the problem the OP has brought to the forum. It is most probable that many of you "moral" people do perfectly legal things, or support popular positions, that I find immoral and highly reprehensible. Does that make you wrong because you don't have the "moral high road" to argue like I do? Even if Evans disagrees with you also?

Once again - the OP problem boiled down to his alarms going off in a way that was distracting or disorienting and turning them off one by one was onerous. This just happened to be caused mostly by docked boats in this particular situation, but is a general issue whenever there are many boats with AIS in close quarters, moving slowly and not maneuvering in a generally straight and purposeful manner.

In other words, in a harbor with lots of boats doing what boats do in harbors - fishing, fooling around, seeing the sights, racing, picking up moorings and dropping anchors, etc.

Even if all docked, moored and anchored boats were not transmitting, the OP's problem will still exist in these situations.

Those of us arguing that the mariner should accept this and develop tactics for it get pilloried on a petard as immoral, etc. I don't understand the connection or logic there.

And as great of a navigator and boat operator as Evans is, some of us do not have his problem and routinely navigate in areas that have worse target "clutter" without problem.

Because we have that experience, we also understand that turning off all AIS units when docked, moored or anchored will not solve the problem. I suspect many of you who are throwing the moral crap around, or think the problem could be solved that way, do not understand this because you have not been in this type of situation regularly.

But you can do a thought experiment. Think of a harbor. Where are the marinas in relation to the fairways and main navigable waters? Why would clusters of targets essentially located on land be causing concern? Why would stationary targets not on your heading and off of the navigable waters cause concern?

It was proposed that I keep telling a porker by saying Evans was navigating in a harbor with his AIS alarms turned on and that he was really in the shipping channel. Evans has not described where exactly he was experiencing his problem, but I have shown that the Newport Harbor marinas and mooring fields are a mile or more from the shipping channel. In this scenario, there is absolutely no cause for concern from those boats. If he was indeed navigating through a harbor, then he was wrong to have his audible alarms on unless he was willing to deal with continually turning them off (and he stated that he was not).

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Old 19-05-2013, 05:33   #315
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pirate Re: Please turn your AIS off when docked/moored/anchored

Quote:
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But Boatman, as a previous poster pointed out on this thread, all of the experienced cruisers are agreeing with Evans and the ones without much experience are the ones that have been disagreeing. So you do not have enough experience.

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And all the experienced cruisers are...??
As Saddam once said... "Allah save me from 'Experts'..."
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