I learned celestial navigation back in the 1970's. My son is a serving naval officer and told me several years ago that the US Navy no longer used or practiced celestial navigation.
The following article is from Defenseone.com and is written by Steve Mollman.
"Satellites and GPS are vulnerable to cyber attack. The tools of yesteryear are not.
Sometimes old school is best. In today’s U.S. Navy, navigating a warship by the stars instead of GPS is making a comeback.
The Naval Academy stopped teaching celestial navigation in the late 1990s, deeming the hard-to-learn skill irrelevant in an era when satellites can relay a ship’s location with remarkable ease and precision.
But satellites and GPS are vulnerable to cyber attack. The tools of yesteryear—sextants, nautical almanacs, volumes of tables—are not. With that in mind, the academy is reinstating celestial navigation into its curriculum. Wooden boxes with decades-old instruments will be dusted off and opened, and students will once again learn to chart a course by measuring the angles of stars."
Read Mr. Mollman's complete post.