stupid question about altitude

standing near the sea, the altitude never calibrated, x6 just bought. is it ok zero the altitude ? or the reference to "sea level" is a technical "thing" and not really "sea level" ?

sorry for the question but it's much easier to get to the sea in my town than get to a "known altitude" point ?

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[Brad]

yes, 0 altitide is ok if your standing at sea level