zoidberg
Well-Known Member
Discussing the challenges to participants in the GGR using only traditional means and equipment, we were puzzled by the practicalities of determining Compass Error during large changes of 'terrestrial and magnetic latitude' - especially when compasses are used with no 'shadow pin' or are bulkhead-fitted, and are anyway designed for use in the Northern 'MN Zone'.
There are other considerations, of large changes in Magnetic Variation and Dip , when large changes are made of latitude and of longitude .....
and
There is some brief reference to addressing such difficulties in the RYA's Ocean syllabus, and demonstration of a 'compass check by sun's amplitude' is expected, but there is AIR no mention of how this might/should be accomplished. I do know that Ocean Examiners have shown interest-in-detail in 'how exactly did you....'.
It may be that GGR racers will have little interest in such esoterica ( for others have circled the globe without such niceties ) until, perhaps, after several weeks without a sight of the sun at sunrise/sunset and Deduced Reckoning, to say nothing of Calculated Longitude, has become 'anyone's guess'. There may well be renewed interest in the Polynesians' 'guiding stars' techniques.....
There are other considerations, of large changes in Magnetic Variation and Dip , when large changes are made of latitude and of longitude .....
and
There is some brief reference to addressing such difficulties in the RYA's Ocean syllabus, and demonstration of a 'compass check by sun's amplitude' is expected, but there is AIR no mention of how this might/should be accomplished. I do know that Ocean Examiners have shown interest-in-detail in 'how exactly did you....'.
It may be that GGR racers will have little interest in such esoterica ( for others have circled the globe without such niceties ) until, perhaps, after several weeks without a sight of the sun at sunrise/sunset and Deduced Reckoning, to say nothing of Calculated Longitude, has become 'anyone's guess'. There may well be renewed interest in the Polynesians' 'guiding stars' techniques.....
