• shalafi@lemmy.world
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    7 days ago

    Been trying to learn about the tides around here so I can tell what I’m seeing on the water. Imagine my joy when I found a Casio, which I collect, with tide and moon phase indicators!

    And that’s when I learned the Gulf Coast is strange, has diurnal tides (twice a day) the watch can’t predict. Took me an hour and a half to figure out it would never function. The moon phase works!

    • Deebster@infosec.pub
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      6 days ago

      the Gulf Coast is strange, has diurnal tides (twice a day)

      Diurnal tides are once a day (semidiurnal is twice a day). By the Gulf Coast, I guess you must mean the Gulf of Mexico. I’m living on the other side of the world in the other diurnal region, so I assume our tides are synchronised!

    • antlion@lemmy.dbzer0.com
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      7 days ago

      Tidal prediction requires a harmonic analysis of observed tides, and its location specific. Not sure how a watch is supposed to do that other than holding a database of tidal coefficients.

      This video contains a lot of interesting history of tidal analysis and prediction:

      https://youtu.be/IgF3OX8nT0w

      • shalafi@lemmy.world
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        7 days ago

        There are adjustments you can make on the watch. Requires tables and whatnot. That’s why it took me so long to figure out it wouldn’t work!

    • Korhaka@sopuli.xyz
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      7 days ago

      Now if you want strange tides look at Southampton. Not very big tides given its in the middle of the channel but the graph is an interesting one to look at.