Marc J. Zeitlin wrote:

To send us off on another tangent, and one that I haven't seen mentioned
in this thread before, it's "ded-reckoning", not "dead-reckoning".

Not according to the OED.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.