Next message: Nels Tomlinson: "Re: Role of CN at sea, was RE: Averaging sights ..."
Isn't the basis of off-shore navigation Ded. Reckoning? Corrected, whenever possible, by 'celestial' and/or
any other methods available: soundings, radio source directions, changed wave patterns, appearance of
land birds, radar, etc, etc, ... and GPS.
The GPS itself might be reliable but small boats are a terrible place for electronics generally; hot and cold,
humid, a corrosive atmosphere, and always being bounced about. In my also 'admittedly very limited
experience' there are an endless number of reasons the GPS doesn't work, few of them related to the
reliability of the system. Corrosion at the outside fitting of the antenna, water inside covering the batteries
(leading to loss of motor) and so on. GPS sits at the top of a tall tree of technology, and is vulnerable to
problems with any of the intervening branches.
Surely navigation is a state of mind, specifically of being aware of progressed position. The machines are
just tools to be used when appropriate and when available. God help anyone who depends exclusively on
them. And She tends to prefer, I've noticed, helping those who help themselves.
Quoting Herbert Prinz <>:
> Lisa Fiene wrote:
>
> > We're planning a passage to the Louisiades next season and yes, we'll be
> > taking our morning noon and twilight sights also, plotting them on our
> > sheets, checking our position against the GPS. Our attitude is that the
> > GPS is a backup, not the other way around.
>
> I do not see how one can maintain this attitude in the face of reality. In
> my
> admittedly very limited experience of ten thousand off shore miles over the
> last
> ten years I have not ONCE been in a situation where GPS didn't work, but cel
> nav
> would. In fact, I have not once been in a situation at sea where GPS didn't
> work.
> Full stop. But I have REPEATEDLY been in situations where celestial was
> unavailable for several days in a row and GPS was the only position finding
> tool
> available. Conclusion: Celestial is not even a backup!
>
> Herbert Prinz
>
