I know the saying about not letting your left hand know what your right hand is doing, but it helps if they both use the same measuring system...
Sometimes, going up to eleven simply isn't enough...
Here's a link to some info about Amsterdam feet and similar units of measurement -
Voet (Old Dutch)
A useful article -
What We Have Here is a Failure to Communicate…. in Ship Construction!
And a couple of cute videos, just in case any of you might be amused by them...