Re: Coast Guard?
Always, always have a backup, and a backup to that backup. Mother Nature is a cruel, heartless bitch, and she will kill you without a second thought if she thinks you're not giving her the respect that she deserves. And that goes double at sea (as the crew of the El Faro, RIP, found out recently).
I'm frankly surprised that the Navy discontinued celestial navigation courses. The Army's still teaching Land Navigation with map and compass.