5 ms·

Yep, exactly what I was thinking. Add a small solar panel and it could probably function for a decade.

LeifCarrotson 7y ago
I think you're underestimating the harsh nature of the ocean. Few things last for a decade on the ocean without frequent maintenance, high up-front costs, or both - and often not even then. There's very little intersection between hardware that would last in those conditions and would be cheap enough that coast guards would be willing to just leave it on a ship. Or maybe I'm underestimating the budget of the Coast Guard, but leaving this thing adrift in the first place seems to indicate otherwise...
- Seenso 7y ago
  > One wonders if you could drop a battery operated GPS beacon reporting by satellite on these things to report back their position once a day once it has been abandoned. Something like that should be able to run for a couple of years at least. >> Yep, exactly what I was thinking. Add a small solar panel and it could probably function for a decade. > I think you're underestimating the harsh nature of the ocean. Few things last for a decade on the ocean without frequent maintenance, high up-front costs, or both - and often not even then. A solar powered GPS beacon may be an exception to that rule. Couldn't you just encase the beacon electronics and the solar panel in a hunk of clear epoxy potting [1], and then secure the thing to the deck with stainless steel screws? For an application like this, it's probably sufficient that the beacon only operate during daylight hours, so you probably don't even need a battery. I don't imagine the electronics would cost much more than that for a PLB [2], so we're talking somewhere in the ballpark of $500. The main expense would be the receiving satellite and sending a helicopter to the ship for installation. [1] https://en.wikipedia.org/wiki/Potting_(electronics) https://en.wikipedia.org/wiki/Potting_(electronics) [2] https://www.rei.com/c/personal-locator-beacons https://www.rei.com/c/personal-locator-beacons
  - shiftpgdn 7y ago
    Even stainless steel will probably fail in the ocean. The sea is an absurdly harsh environment. Look up sacrificial anodes or ultra high corrosion resistant alloys to get an idea of what you need to keep stuff going even for just a few years.
    - dasv 7y ago
      We had a monitoring unit in a heavy aluminum box on a buoy a couple km off Biscay (the HARSHLab, heh...) that lasted half a year, until the stainless bolts corroded against the aluminum and the lid flew right off. Polycarbonate boxes have worked better for us.
      - shiftpgdn 7y ago
        Won't the polycarbonate suffer UV degradation?
- ChuckMcM 7y ago
  I agree with you that ocean beacons are treated harshly. That said, we have an interesting exemplar of a battery powered beacon that reports in daily in the NOAA sea buoy transponder package.
- dasv 7y ago
  Tuna radar buoys are dropped regularly in the sea, and are quite a bit north of $500, I believe. They are not expected to be recovered, work completely off solar, and are closed solid. You need a magnet to turn them on through a reed switch, they don't even have a hole for a button to prevent water ingress.

I think you're underestimating the harsh nature of the ocean. Few things last for a decade on the ocean without frequent maintenance, high up-front costs, or both - and often not even then. There's very little intersection between hardware that would last in those conditions and would be cheap enough that coast guards would be willing to just leave it on a ship. Or maybe I'm underestimating the budget of the Coast Guard, but leaving this thing adrift in the first place seems to indicate otherwise...

Seenso 7y ago
> One wonders if you could drop a battery operated GPS beacon reporting by satellite on these things to report back their position once a day once it has been abandoned. Something like that should be able to run for a couple of years at least. >> Yep, exactly what I was thinking. Add a small solar panel and it could probably function for a decade. > I think you're underestimating the harsh nature of the ocean. Few things last for a decade on the ocean without frequent maintenance, high up-front costs, or both - and often not even then. A solar powered GPS beacon may be an exception to that rule. Couldn't you just encase the beacon electronics and the solar panel in a hunk of clear epoxy potting [1], and then secure the thing to the deck with stainless steel screws? For an application like this, it's probably sufficient that the beacon only operate during daylight hours, so you probably don't even need a battery. I don't imagine the electronics would cost much more than that for a PLB [2], so we're talking somewhere in the ballpark of $500. The main expense would be the receiving satellite and sending a helicopter to the ship for installation. [1] https://en.wikipedia.org/wiki/Potting_(electronics) https://en.wikipedia.org/wiki/Potting_(electronics) [2] https://www.rei.com/c/personal-locator-beacons https://www.rei.com/c/personal-locator-beacons
- shiftpgdn 7y ago
  Even stainless steel will probably fail in the ocean. The sea is an absurdly harsh environment. Look up sacrificial anodes or ultra high corrosion resistant alloys to get an idea of what you need to keep stuff going even for just a few years.
  - dasv 7y ago
    We had a monitoring unit in a heavy aluminum box on a buoy a couple km off Biscay (the HARSHLab, heh...) that lasted half a year, until the stainless bolts corroded against the aluminum and the lid flew right off. Polycarbonate boxes have worked better for us.
    - shiftpgdn 7y ago
      Won't the polycarbonate suffer UV degradation?
ChuckMcM 7y ago
I agree with you that ocean beacons are treated harshly. That said, we have an interesting exemplar of a battery powered beacon that reports in daily in the NOAA sea buoy transponder package.
dasv 7y ago
Tuna radar buoys are dropped regularly in the sea, and are quite a bit north of $500, I believe. They are not expected to be recovered, work completely off solar, and are closed solid. You need a magnet to turn them on through a reed switch, they don't even have a hole for a button to prevent water ingress.