I think that anything offered is as an aid to navigation which neatly sidesteps any liability.
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Throughout this discussion there is no equivalence to a the information available to the user sailing from the Eastern Anchorage Singapore to proceed to the East. The radar is saturated with hundreds of targets, anchored and underway and the bridge team moving from a night vision destroying the night vision of the command nothing matches a properly adjusted EQDIS display showing the ARPA and AIS information. My wife has just informed me that that the cat has just brought a large dead rat into the house for approval that requires my immediate attention. How the mantle of command passes!
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This probably don’t solve all navigation problems, (real or perceived) but it may help for some:
It is sometimes helpful to know a ship’s destination, but that info is usefully available on the AIS. Sometimes in error of course, like everything else.
I have that now.
Collision alert, the CPA that sets this off can be varied.
I’ll pass on the AI “guess what the boat will do next” features, it won’t be accurate and would drive me nuts.
Something I just realized,
The screenshot above shows a tug southbound with a long tow. If the northbound vessel likes the 0.47 mile CPA and does not alter course, there is some chance they’ll hit the tow that is presumably way back behind the tug.
- not that I did that, but I do have a plot somewhere of a quick tack away once I realized how far back the tow was
** OpenCPN can do radar overlay which would show the tow, but it isn’t on for this screenshot
When you are discussing radar/AIS fusion, do you mean this simple overlay or tagging the green AIS target and moving it around with the red radar target between AIS hits?
I can see some issues like rain or sea clutter causing the AIS tag to jump to one of the nearby targets or something.
Radar/AIS fusion is a weighting algorithm that combines the AIS and ARPA vector information and displays one unified collision avoidance dataset (at least this is what it was on the Wartsila Nacos Multipilot Platinum).
The previous solution (like on the Transas Navisailor 4000 or something of that vintage) is to just ARPA and AIS tag the same contact and see how the two vectors overlap on the ECDIS.
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Personally I’m much happier with this method. AIS and ARPA don’t update at the same rates, and sometimes the variance can be useful to see. It’s also easy to see which data is derived from which source.
@yacht_sailor here are two screenshots from my phone, taken perhaps a minute apart; the green vector is the MARPA fix on the container ship. Since a radar plot is a moving average over time there was a bit of lag before it caught up with the AIS data.
Deep-sea commercial vessels have more screen real estate than the typical small vessel, don’t have to pick just one way to display information.
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According to IEC 61174:2015 “If both tracked target information and AIS target information are displayed at the same time on the ECDIS, then ECDIS shall display them as a single target according to Annex A of IEC 62288:2014.”
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