NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Role of CN at sea
From: Dan Allen
Date: 2004 Oct 13, 10:47 -0600
From: Dan Allen
Date: 2004 Oct 13, 10:47 -0600
Agreed! I just know that when the GPS unit I had failed, it took me quite by surprise. In my case I was just using it recreationally so no great loss. The point is that they can and do fail and one must plan for that. The reasons you give below are why sextants are fast disappearing, but I still enjoy them. They are so completely different in their approach to navigation from a GPS that if an electromagnetic pulse (EMP) were to occur, I could still navigate with my sextant on a clear day while everyone else would just be staring at their GPS wondering why it did not work, much the way I did years ago. (I will point out that I have since owned at least 7 other Garmin GPSes and none of them have ever failed like that first GPS 40 did in 1995.) -----Original Message----- From: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Jared Sherman Sent: Wednesday, October 13, 2004 10:35 AM To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: Re: Role of CN at sea Dan- I don't know the mortality of the GPS birds, offhand I hadn't heard of ANY failures in them. And, there are spare birds kept in orbit so that even if one or two failed "now" they could be replaced as soon as the spares shifted orbit, no need for launching anything. It is, after all, a hardened military system designed for combat performance--not a consumer device allowed to casually fail. On the flip side, i.e. "What if the GPS unit fails" I think that's a poor question, best answered by the reply "What if you drop your sextant?" The sextant is instantly trashed, the GPS usually continues to work. www.bestbuy.com has been clearancing Garmin eTrex units for $49.95. At that price, you can buy 4 GPSes, two solar battery charger sets, cushioned afloat pouches, and a couple of hundred premium AA cells for the price of one lowest-price metal sextant. Then of course, there is the other problem with a sextant: What if the navigator fails?! Gets sick, hit in the head, is thrown overboard by the cook? The sextant is useless without a trained operator. The GPS can often be coaxed into providing some useful information in a few minutes, by anyone else on board.