NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: What do offshore recreational navigators really do?
From: Jared Sherman
Date: 2005 Jun 7, 19:42 -0400
From: Jared Sherman
Date: 2005 Jun 7, 19:42 -0400
<> Trivial exercise, Peter. NiMh AA cell, capacity now about 2300mAh, price about $3.50 each and less in bulk. $14 for one set of 4xAA cells. They will keep a GPS alive without use over the non-sailing season, i.e. 6 months. And that capacity is enough for some 12-24 hours of constant use in most GPSes. (Or 48 hours for a unit that uses only 2 batteries.) Add a solar charger for $25, able to recharge that set of 4xAA in a day or two. So...let's say you buy 4 solar chargers for redundancy, 4 sets of batteries to keep all the GPSes loaded, and five spare sets of batteries for each GPS. 24 sets of batteries, $336, probably $250 as a bulk order. $350 including the four chargers. Plus $500 for the four GPSes. Total? $850 for four GPSes with "perpetual power" to last at least five years between the units and spares with near-constant use available. And most of us would consider that to be way overkill on the redundancy, especially compared to "What, you only have one sextant?". By going to a more restrained pace, one could figure perhaps taking four or six GPS "shots" each day, and even the GPS wrist watches will do something like 600 shots one one battery. Using a low-power GPS and a restrained energy budget...no big deal. AA cells are also fairly universal on this planet, if someplace doesn't have them, something can always be improvised, like a FreeCell hand-cranked charger. Or a water or wind wheel supplying ship's power...and so on. Yes, it is nice not to need electronics. But they needn't be problem children.
