by Nancy Knudsen
The instructor who taught me celestial navigation many years ago started every class by saying 'When the GPS has fallen into the bilge...' thus justifying his insistence that every sailor who adventures into an ocean needs a knowledge of classical celestial navigation.
Now Coastguards are warning sailors again of the danger of relying on satellite navigation alone, after a rescue helicopter winched the crew of a yacht to safety off the Essex coast in the UK this week. 'A vessel's position and track should be regularly plotted on a chart and a backup navigation system employed during an offshore passage.' said the Thames Coastguard Watch Manager Mark Baker.
Rescuers said a 25 ft yacht - called Nelly - ran around off Bradwell-on-Sea in bad weather late on Saturday after their single GPS failed.
Three crew members were winched to safety by the RAF after lifeboatmen were unable to reach the boat, said coastguards.
'The yacht's GPS navigation equipment had failed and the crew could only make a very rough estimate of their position,' said a spokeswoman for the Maritime and Coastguard Agency.
'Due to the severe weather conditions and breaking surf battering the yacht, the three occupants of the yacht were winched from the vessel and evacuated ashore.'
Mark Baker added: 'This incident highlights the risk of relying solely on a single GPS navigation unit.'
Certainly anything that will avert the need for rescue crews to risk, potentially, their own lives unnecessarily is very desirable.
Mastering the art of celestial navigation is not the easiest task, and many hundreds of cruising sailors now set forth with only a GPS system as navigational support.
Multiple GPS systems are of course a help, but even these have been known to fail with a direct lightning strike, with or without the best lightning protectors, and with or without the GPS being connected directly to the yacht.
A microwave oven has been often suggested as a suitable receptacle for your spare GPS.. If there is any sailor reading this who can report having actually preserved a GPS in this way, we at Sail-World would like to hear your story.
................................................................ Letter from Reader:
Sender: Clint Collier
> Message: Oh, and what happens when the sextant is dropped overboard? Go
> back to the astrolabe? When the radio gets wet start practicing your
> Morse code... oh, wait, the CG doesn't speak Morse code any more!
> Celestial navigation is a nice art to be familiar with and, play with but
> if you are concerned with dropping your GPS into the bilge the first thing
> you should do is run out and buy a backup GPS, not take a celestial
> navigation course.
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1:21 PM Wed 5 Nov 2008 GMT
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