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Old 31-08-2017, 16:25   #46
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Re: AIS Man Overboard Behaviour

So your concern is that a vessel proceeding on autohelm will, on receipt of a SART turn itself around, potentially crash gybing or chucking another person over the side, and then in the worst case run your MOB over too. My current NAV system wouldn't do this (you have to manually advance waypoints) so I hadn't thought of that.

The situation in that file was the start of a RORC race in a Fastnet year, so you're seeing something like 80 yachts all required to carry AIS transponders by the committee. It is not normal, but what is not uncommon is for a large fleet of yachts in loose company to cross the English Channel at night, something common for passage races everywhere (or cruising in company). Maybe some form of highlighting could be useful, or maybe a more evocative icon, a bright red figure waving for example, or maybe there is a common ECDIS icon that exists?

On the navigation front, for my personal purposes I'd like to be able to set a default behaviour for an AIS SART that I have told the program is from my boat to set off an alert and tell me where they are without me having to go below (the E80 we have is too old to display SARTs as far as I can tell, so OpenCPN is my only receiving method).

What I think might be better as a more general case is for an AIS SART to on the acknowledge window offer a "Navigate to SART" button for a SART that is not programmed to be one of your personal SARTs, and for a different alert, maybe one that says "Man Overboard!" with the options to "Cancel Future Alerts", "Navigate To", and "Acknowledge" to pop up for a SART that you've tagged to your vessel.

On the letting computers make the decision front that all comes down to careful programming of constraints, and which ones it is allowed to break or not! Where you have a person in the loop is interesting too.
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Old 31-08-2017, 16:39   #47
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Re: AIS Man Overboard Behaviour

Firebar,

Good comments.

I agree that when the MOB pops up it would be good to have a navigate to MOB button. I will think about the implications.

When O is driving an autopilot it is really driving the autopilot. There is not another box in between that a human has to give an OK or anything. So when O is navigating to a waypoint it is driving the helm via XTE messages.

Presently I believe an unknown SART pops up a window but does not automatically build a route. A route is built only for known SART in the MMSI list marked as MOB. So it pretty much works the way you describe.

I'm not sure about canceling future alerts. I would feel better not doing that. After all, an AIS SART is not going to ping you from more than a few miles away. They don't reach nearly as far as regular AIS. So the odds of getting a real AIS SART that you would simply ignore are pretty low I would guess.
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Old 31-08-2017, 17:54   #48
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Re: AIS Man Overboard Behaviour

Quote:
I agree that when the MOB pops up it would be good to have a navigate to MOB button. I will think about the implications.


Unknown MOB
, popups of AlS Alert, Target Info and Target Query should have "Navigate to MOB" button, or "Route to MOB" (requires activation) button, without having to find the route and activate it which during emergency would be more stressful.

Quote:
When O is driving an autopilot it is really driving the autopilot. There is not another box in between that a human has to give an OK or anything. So when O is navigating to a waypoint it is driving the helm via XTE messages.
Ok, Don't make the buttons do "Navigate to MOB" make them do "Route to MOB" which requires activation.

Quote:
Presently I believe an unknown SART pops up a window but does not automatically build a route. A route is built only for known SART in the MMSI list marked as MOB. So it pretty much works the way you describe.
Exactly right. So something needs to be done about the "unknown" MOB case.

Quote:
I'm not sure about canceling future alerts. I would feel better not doing that. After all, an AIS SART is not going to ping you from more than a few miles away. They don't reach nearly as far as regular AIS. So the odds of getting a real AIS SART that you would simply ignore are pretty low I would guess.
It would be a mistake to limit the number of alerts I think. The most current alert is the best one. Also the trail of alerts gives excellent set & drift information and will help with recovery. Additionally, the old Sart alerts should be left "enabled" but be changed to an orange color, IMHO to provide set & drift information.

This summer my purchase of an ACR AIS/DSC MOB PLB after a rosey sales speal, was a mixed experience, due to reading the fine print afterwards....the statements were outrageous, essentially saying you could not depend on it, and limiting ACR liability to up until it is deployed! I called the company to determine if there were any practical tests done in rough water, and was only given the fact that it had passed a certain Federal requirement, and to contact them. I was hugely disappointed, but more than that, I was left with the belief that I should have purchased a true 403 SART. because I was left with little confidence that it would work properly.

I wonder if anyone has actually tried this device and would like to know better what to expect? 1nm, 2nm, 3nm when you hold it up in large waves? Time to deply? Distance of boat at normal speeds, when deployed?

Quote:
The cluttered scenario in Firebar's VDR file is atypical. We should not make hasty changes based on it. A MOB in that situation will be picked up. There are dozens of boats nearby.
I think it would be best to expect these kinds of conditions as the MOB still needs to be picked up! I believe these conditions can be improved by the following "quick change" additions to MenuBar > AIS:
  • Show Target COG Predictor Arrow to Show/Hide
  • Show CPA TCPA to Show/Hide.
I will be adding these requests to Tracker.
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Old 31-08-2017, 18:51   #49
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Re: AIS Man Overboard Behaviour

TDan:
Quote:
The cluttered scenario in Firebar's VDR file is atypical. We should not make hasty changes based on it. A MOB in that situation will be picked up. There are dozens of boats nearby.
Touche. ...I agree with you of course.

I do think that things can be improved with some simple "quick change" additions to MenuBar > AIS dropdown:
  • "Show Target COG Predictor Arrow" checkbox to Show/Hide predictors. (This would be easy)
  • "Show CPA TCPA" checkbox to Show/Hide CPA TCPA. (Since this is a quick change display thing, I think it would be acceptable practice, when hunting for a SART.)
These probably won't be done now, although one could be quite easily, so I guess they should go into the TRACKER.

In addition to that, I'd like to be able to set the default route colors and thicknesses, etc.


Also I do think the SART documentation in this paragraph https://opencpn.org/wiki/dokuwiki/do...e_is_activated
needs to be shortened up.
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Old 01-09-2017, 10:22   #50
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Re: AIS Man Overboard Behaviour

Quote:
Originally Posted by transmitterdan View Post
When O is driving an autopilot it is really driving the autopilot. There is not another box in between that a human has to give an OK or anything. So when O is navigating to a waypoint it is driving the helm via XTE messages.
I think that the XTE thing is true with newer systems, but the Raymarine S1 that we have will beep frantically a you when you give it a new waypoint (I think it's reading the names from the WPL sentences?) and will contine to hold a course until you accept the next waypoint. That is however irrelevant to your concerns I think.

Maybe a good way of doing things would be to have a "Man Overboard!" alert popup which does a "Route To" option, with a follow up "Activate Navigation?" popup.

Quote:
Originally Posted by transmitterdan View Post
I'm not sure about canceling future alerts. I would feel better not doing that. After all, an AIS SART is not going to ping you from more than a few miles away. They don't reach nearly as far as regular AIS. So the odds of getting a real AIS SART that you would simply ignore are pretty low I would guess.
My thoughts on cancelling the alerts was that I have only ever seen a SART set off by accident, and that multiple times (about 5 since March), let me have a way of removing the activation for when it's been cancelled, or at least having future alerts (within that 18 minute window) not set off lots of alarms and whistles.

Maybe for a SART in the MMSI list there could be a "New MOB Position" message with the options of "Route to", "Navigate to" and, "Acknowledge" after you have acknowledged the first time.

Quote:
Originally Posted by rgleason View Post
This summer my purchase of an ACR AIS/DSC MOB PLB after a rosey sales speal, was a mixed experience, due to reading the fine print afterwards....the statements were outrageous, essentially saying you could not depend on it, and limiting ACR liability to up until it is deployed! I called the company to determine if there were any practical tests done in rough water, and was only given the fact that it had passed a certain Federal requirement, and to contact them. I was hugely disappointed, but more than that, I was left with the belief that I should have purchased a true 403 SART. because I was left with little confidence that it would work properly.

I wonder if anyone has actually tried this device and would like to know better what to expect? 1nm, 2nm, 3nm when you hold it up in large waves? Time to deply? Distance of boat at normal speeds, when deployed?
Well there was the guy rescued in the Clipper Race that was only found because of his AIS beacon, a 403 wouldn't have given the real time position info to the people pulling him out before hypothermia set in. Our crew has a mix of 403 EPIRBs and AIS SARTs, I think for our racing the SART is better because there's so many boats around, but for cruising I'd love a combination AIS/403 EPIRB, but I think there's a conspiracy to not make them so you have to buy both.

On the wave and holding up thing I'd really like to see a commercial arrangement like the SARBE that the RAF has for fast jets, that's a pouch on the webbing of the lifejacket which the beacon sits in, an antenna cable concealed behind the bladder, and an antenna mounted on the bladder itself, it folds out when the jacket inflates and automatically triggers the beacon.
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Old 01-09-2017, 10:59   #51
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Re: AIS Man Overboard Behaviour

Good idea.

Quote:
an antenna cable concealed behind the bladder, and an antenna mounted on the bladder itself, it folds out when the jacket inflates and automatically triggers the beacon.
The issue is line of sight to SHIP when the MOB is in big waves. It is very helpful that the VHF/AIS is likely pretty high up.

Is there any common expectation/experience about range with these devices?

I've added a new Tracker Item for AIS
FS#2272 - AIS Display "quick change" control from Menubar > AIS dropdown

Please comment and Vote for it. Thanks.
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Old 01-09-2017, 11:30   #52
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Re: AIS Man Overboard Behaviour

Quote:
My thoughts on cancelling the alerts was that I have only ever seen a SART set off by accident, and that multiple times (about 5 since March), let me have a way of removing the activation for when it's been cancelled, or at least having future alerts (within that 18 minute window) not set off lots of alarms and whistles.
What about adding another item to
FS#2272 - AIS Display "quick change" control from Menubar > AIS dropdown

-"Suppress SART MOB Alerts" ?


I expect there will be a howl, but that would do it.
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Old 01-09-2017, 14:18   #53
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Re: AIS Man Overboard Behaviour

If you want to suppress SART MOB alerts just uncheck that MOB device in the MMSI list.

It will then revert to a standard SART alert but will not create automatic routes. After the AIS timeout period it will disappear on its own.

I will think about this some when I have more time.
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Old 01-09-2017, 16:30   #54
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Re: AIS Man Overboard Behaviour

Quote:
Originally Posted by transmitterdan View Post
If you want to suppress SART MOB alerts just uncheck that MOB device in the MMSI list.

It will then revert to a standard SART alert but will not create automatic routes. After the AIS timeout period it will disappear on its own.

I will think about this some when I have more time.
Great. It does need some thought.

Options > Ship > MMSI Properties > Double click on SART-MOB > Uncheck "Handle this MMSI as SART-MOB" which is a total of 5 selections and mouse clicks, which basically stops creation of the Temporary MOB Route, but does not stop the SART alerts in my testing.

What about a right click on the SART MOB, and Pick "Suppress SART Alert"
Is this something we should request in Tracker?

Also I have revised the SART page again. Please review and advise.
https://opencpn.org/wiki/dokuwiki/do...ttons:ais:sart
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Old 01-09-2017, 17:52   #55
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Re: AIS Man Overboard Behaviour

How about using the AIS Target List to disable SART MOB Alert? with a Right Click?
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