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    Re: News Item on Over-reliance on GPS
    From: Fred Hebard
    Date: 2008 Nov 7, 15:59 -0500

    Very nice post Peter.  It's very nice to have one's faith in the
    utility of sextants on small boats restored now and again.  I wonder
    whether Frank were trolling for such a response!
    
    Fred
    
    On Nov 6, 2008, at 5:33 PM, Peter Fogg wrote:
    
    >
    > Frank you asked: First, may I ask, just for the sake of comparison,
    > is your chronometer
    > electronic?
    >
    > You may, Frank.  Have both kinds of watches, electronic and
    > mechanical, and note that my recently acquired Casio promises a 10-
    > year battery life (4-months with me now, and seems to have settled
    > down to about a consistent 1.5sec/month gain.  If its not a
    > chronometer its still a pretty good watch).
    >
    > I have often found people extolling the virtues of celestial
    > navigation because it is immune to electrical outages who
    > nonetheless carry
    > only battery-powered watches. You've mentioned previously that you
    > do a
    > survey of the timepieces of everyone on board at the beginning of a
    > passage,
    > and that's a great idea. But do you consider yourself at risk if all
    > timepieces are battery-powered?
    >
    > Risk of .. all their cells failing at much the same time?  Seems
    > a .. remote risk?  The on-board survey, incidentally, is ongoing,
    > so an idea is gained of individual watch error and, if the passage
    > is long enough, rate of change.  So even if all the other
    > timepieces onboard fail to proceed, plus we have no radio, the last
    > one going should still give us fairly accurate time, after
    > correction.  I should say that the assumed-to-be-correct time comes
    > from the GPS !
    >
    > Lets say the GPS dies, or a difficult to track-down error develops
    > with its antenna-mounting connection out on the rail (personally
    > experienced) or the boat runs out the vast numbers of cells needed
    > for portable GPS continuous operation  (did you realise that those
    > gadjets have an inordinate appetite for difficult-to-replace-at-sea
    > cells?).  The result is: no GPS.  Have experienced just that - no
    > working GPS - on a well-found boat that was carrying 3 of the silly
    > things, including a portable device.
    >
    > What actually happens, its been all to common on so many different
    > boats I've sailed on, is that for a variety of reasons the sole
    > (the floor of the cabin) becomes covered in water.  This is usually
    > very bad news for the batteries that are typically stored beneath
    > the sole.  No battery life usually means you can't get the diesel
    > motor going, and in one fell swoop you are, for most practical
    > purposes, transported back to the 19th century.  You'd better have
    > a good supply of everything you need for a happy passage that
    > doesn't rely on electronics, because from that point on there ain't
    > any, subject to individual cell life and supply.
    >
    > We thought we were so clever in our little boat, as we had every
    > reason to believe it didn't leak (fibreglass hull and cabin) plus a
    > different motor configeration, without batteries beneath the sole.
    > We spent a long day once punching into waves, sailing upwind, and
    > after 14 non-stop hours of that I went below for a rest, stepping
    > into cold water in the dark as I reached the sole.  So climbed back
    > up and shared this good news with Annick:
    > "Houston, we have a problem".
    >
    > It wasn't too serious, happily, and after I bailed out the boat the
    > water only came back slowly.  So much for not leaking !  All the
    > cabin windows plus the forward hatch were streaming only a little
    > of the green water being regularly dumped on them.
    >
    > All boats leak, given enough encouragement.  What also happens
    > often enough is that they get pooped, a wave hits from behind and a
    > lot of that water goes below through the hatch, if careless sailors
    > have left it open.
    >
    > Or you may have a problem with fuel.  Algae seems to thrive in
    > diesel fuel, especially in practice onboard, despite the stuff
    > added to discourage it, and when enough grows it clogs the supply
    > line and stops the motor.  The end result may be the same: no
    > electronics.
    >
    > Electonics? - wonderful wizardry.  Marvelous.  Fabulously clever
    > gadgetry, that increases our quality of life hugely.
    >
    > Reliable?  Out at sea in a small boat?  In your dreams ...
    >
    > >
    
    
    
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