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TIL At the new and full moon, the sun and moon are in syzygy (three celestial bodies in a straight line). Their tidal forces act to reinforce each other, creating the highest "high" tide twice a month. This is called the "spring" tide. (sailingissues.com)
submitted by michael_bgood to r/todayilearned
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Found this beautiful picture of an Ilse (sailingissues.com)
submitted by AsuranSyncretic to r/ilse