On any US Navy warship, there will be plenty. Nobody makes QM3 without that knowledge. At least when I was in the Navy they didn’t and I very seriously doubt things have changed that much now.
I do recall hearing that the GPS was installed far away from the navigator’s table precisely to keep the QMs and the bridge crew from relying on it.
When I was in and I doubt it's changed that much the electronics were temperature critical. By that I mean they could not take a real high heat stress. The gyro {part of the navigational system} on our ship did have back up A/C. I know because I installed several compressors for that back up.
When things go bad like loss of power you go back to manual back ups. That means charts in this case. With steering it's manual operation of the port and starboard steering gears.
Loss of generation means loss of A/C it's that simple. A carrier has about 1800 Tons cooling capacity maybe more on some. Loose it and the electronics don't like it.
A carrier can limp on with the island gone and three fourths of it's boilers or rather reactor capacity out of commission. Engineering has Secondary CON system as well. The A/C's though are very high load demand on start up. We're talking from 1000-1600 amps at 460 volts start current and 175-300 amps run for each unit with up to 10 units on some carriers. So much so we had to call Central to the Electrical Load Dispatcher before hitting start.
Now the other reality as another person mentioned. In battle you can bet the navigational birds will be hit. Old mechanical skills are bomb proof as long as the squid has his instruments and charts to guide him. Electronics are great but can never be the sole system the ship depends on.