"Dead Reckoning" is more accurately written Ded Reckoning, as it is an abbreviation for Deduced Reckoning. sailors us this term to note their position on a chart when they have no other positional fix. Ded Reckoning is best summarized by: "I think I've gone this far in this direction, but I have no way of checking the accuracy of that." Once you can take a fix, either from surrounding landmarks or celestial navigation, you update that position with a more accurate one, and note how you confirmed it. Then you start your next Ded Reckoning from that point...
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