On Sep 16, 6:51 am, wrote:
I was just told by a friend that I should learn celestial
navigation before sailing around the world because
GPS devices don't work that well in the middle of the
ocean and can malfunction if they get wet, etc.

Does my friend have a point even if I intend to bring
3 independent GPS systems with me ?

How about if I just get a cheap sextant and the book
"Celestial Navigation When Your GPS Fails" and
bring them with me ?

TIA

Sure, learn celestial navigation. Or group theory, or some other
arcane area of knowledge. Or bring some good books, like Moby Dick.
It gets pretty boring out there in the wide blue sea. But learn
celestial navigation as a backup for GPS? You've got to be kidding.
First, GPS works great in the middle of the ocean -- and everywhere
else, for that mattter. Second, definitely bring backup GPS units--
we have 3 aboard, in addition to our primary one. Put one in your
ditch bag and remember to inspect it regularly to see the batteries
are good. But don't worry about the satellite system failing -- the
US Government (and everybody else, from commercial airlines to
farmers) is too reliant on GPS to let it fail (or turn it off, which
is what the Europeans seem to fear).

It's celestial navigation that fails, mainly because it depends on
clear skies, which, in the middle of a storm, there ain't any of. One
reason the Carolina coast is littered with shipwrecks is that the Gulf
Stream is almost always covered with clouds, so those ancient mariners
went for days on dead-reckoning -- and with a 2-knot current with lots
of swirls and eddies, that's not a good thing. If they'd had GPS,
they would have been far less likely to run onto the sandbanks.

Good luck on your circumnavigation. See you out here.

Rob