NavList:

My sense is that for medium-high precision work (4 significant digits) circular (or more accurately spiral) slide rules were needed.  For even higher precision (4-5 significant digits) you needed a Fuller or Thacher.  

So, while not particularly popular, they did fill a required niche.

Re: Celestial Navigation in the Movies
From: Paul Dolkas
Date: 2022 Jun 22, 18:49 +0000

Alan-

 

I think the only folks who really got into circular slide rules are (were) pilots, who liked them because they were faster, even though less accurate.  (One really doesn’t need to know the exact time one is going to run out of fuel after all.) Proficiency in the venerable E6-B is still required for a pilot’s license the last time I checked, and of course they also make for a lovely bezel on one’s watch.

 

-Paul