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Comment by GekkePrutser | Hacker News Reader

Whoa... I had no idea that submarine software was this bad. Not just the lack of warnings but also "Waits for VMS to load the next screen, which can take minutes.". Why do you have to wait minutes to load a map?? And why is this running Windows XP?

I'm also surprised there's no contour lines between the depths (although perhaps this is done to not infer a knowledge of depths in the intermediate points where perhaps there is no such knowledge).

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> I'm also surprised there's no contour lines between the depths (although perhaps this is done to not infer a knowledge of depths in the intermediate points where perhaps there is no such knowledge).

Yes, contour lines would imply accuracy that isn't there. The depth numbers indicate positions where the depth was actually measured. Any other location that doesn't have a number was not measured. Bear in mind that even if you have a depth number on your chart, it might be old and out of date. Safe navigation is never guaranteed. And subs never run depth-finder sonar when on patrol.

How do depth numbers get out of date?

Sedimentation?

Underwater volcano eruption?

Continental drift?

The broken assumption thee is that the ocean floor doesn't change. Things are changing all the time. Faster and faster as you get shallower and shallower.

Shipping channels and shallows need to be resurveyed constantly or you have no idea what you might encounter.

It's also worth noting that the waters where depth accuracy is most important to a submarine are also the places where the depth is more likely to change (estuaries, ports, especially new/expanding/busy ports).

Tides & currents moving the bottom (sand, etc.) around, mostly. But it's also possible for a coral reef to have grown taller. Or a volcano, I suppose. :)

NOAA's Chart No. 1 explains the symbols used on charts.

https://www.nauticalcharts.noaa.gov/publications/docs/us-cha...

IIRC the military actually got a private extension to XP's EOL from Microsoft just so that they don't have to change all that tech.

Oh really but even still up to now?? I mean the EOL was in 2014. How long do they keep that up? :)

I suppose they do what we do in our factories at work. Airgapping and extremely strict firewalling where any access is needed.

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