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See my previous comment [0]: "that would release some sort of buoy, that would float to the surface and start transmitting with gps etc." That should work if i

by vlod 3y ago

See my previous comment [0]: "that would release some sort of buoy, that would float to the surface and start transmitting with gps etc." That should work if it's floating I would think? [0] https://news.ycombinator.com/item?id=36409802 https://news.ycombinator.com/item?id=36409802

vel0city 3y ago
I wonder what the drift would be like if you released a buoy 2 miles below the surface. You could theoretically have the last estimated location of the sub, but even then that's largely an estimate as its not like the sub actually has a GPS fix its all dead reckoning. They already know about where the sub should be, somewhere around the Titanic wreck. If an untethered buoy pops up a few miles away, does it really do much to help clue you into where they are? And if its not much to put a tether on the buoy, why not just have the craft be tethered from the start?
- silisili 3y ago
  I tried to research, but it's not clear. It says the gulf stream can reach 5mph, but also that that is near the surface, and it's slower the deeper you go. A buoy ascends at 2.8 m/s. 3000m would yield, meaning about 18 minutes of rise time. If we assume that water is at max speed the whole way through, we'd be talking about 1-2 miles. Realistically, because most of its rise is in deep sea conditions, I imagine it'd be less than 1 mile. But, if it made contact as soon as it reached surface with a GPS location, I'm sure some scientist could calculate about how far it drifted from the water conditions. I'd imagine they could get it down to a few hundred foot radius?
  - vel0city 3y ago
    That's neat, thanks for that information. This suggests such a buoy probably would be useful.
- bobmaxup 3y ago
  https://dosits.org/people-and-sound/communication/how-is-sounds-used-to-transmit-data-underwater/ https://dosits.org/people-and-sound/communication/how-is-sou... https://dosits.org/galleries/technology-gallery/navigation-technology/underwater-gps/ https://dosits.org/galleries/technology-gallery/navigation-t...

by vlod 3y ago

vel0city 3y ago

I wonder what the drift would be like if you released a buoy 2 miles below the surface. You could theoretically have the last estimated location of the sub, but even then that's largely an estimate as its not like the sub actually has a GPS fix its all dead reckoning. They already know about where the sub should be, somewhere around the Titanic wreck. If an untethered buoy pops up a few miles away, does it really do much to help clue you into where they are? And if its not much to put a tether on the buoy, why not just have the craft be tethered from the start?

silisili 3y ago
I tried to research, but it's not clear. It says the gulf stream can reach 5mph, but also that that is near the surface, and it's slower the deeper you go. A buoy ascends at 2.8 m/s. 3000m would yield, meaning about 18 minutes of rise time. If we assume that water is at max speed the whole way through, we'd be talking about 1-2 miles. Realistically, because most of its rise is in deep sea conditions, I imagine it'd be less than 1 mile. But, if it made contact as soon as it reached surface with a GPS location, I'm sure some scientist could calculate about how far it drifted from the water conditions. I'd imagine they could get it down to a few hundred foot radius?
- vel0city 3y ago
  That's neat, thanks for that information. This suggests such a buoy probably would be useful.
bobmaxup 3y ago
https://dosits.org/people-and-sound/communication/how-is-sounds-used-to-transmit-data-underwater/ https://dosits.org/people-and-sound/communication/how-is-sou... https://dosits.org/galleries/technology-gallery/navigation-technology/underwater-gps/ https://dosits.org/galleries/technology-gallery/navigation-t...