From: "Keith" <kemmons@houston.rr.com> Subject: [PUP] Celestial Navigation? I just finished a class on Celestial Navigation and it was a lot of fun and eye-opening. That stuff is hard! Well, at least at first. One thing for sure, I'll have to practice it to keep the skills up. How do you folks feel about Cnav as a backup? Or is everybody just going to carry a bunch of spare GPS' in faraday cages? ------------------------------------------- It is hard. I also passed the USPS Jr Nav class. I try to take a sight once a month underway just to remember how to reduce a sight. The thing I learned is the number of days where you can see the horizon and the sun/moon/star or planet at the same time is pretty small. In Jan in the Pacific conditions where is was possible to take a sight occurred once every 1-2 weeks! Even though long period swells are not an issue for comfort, they still kill the ability to find the horizion. I keep one on board, but now understand why their are so many wrecks on the Pacific coast! Yes I have 2 built in GPS's in the pilothouse, one networked, one standalone. One backup one not plugged in to anything, including power. Finally I keep one in a steel box. I keep the GPS in case the government or a bug shuts down the GPS system. Is it useful, yes. The amount of security it provides depends on the rise that the GPS system is shut down. But to really add value you need to have lots of other redundent systems for more frequent failure modes. Engine, autopilot, DC system alternator etc. Just like a pilot needs to fly instrument approaches to be legal to fly an actual approach, I believe you need to practice Ces Nav. I practice it, but I am not looking forward to depending on it! Scott Strickland Strickly for Fun Nordhavn 47.