bilbobaggins
N/A
Might I offer a suggestion?
In days of yore, sailing masters had precious little else as 'aids to navigation' than their skills at 'Ded. Reckng.' They practised hard, and mulled over their results. Consequently, they knew much of the time what accuracy they could expect in differing conditions, and with that came confidence in their judgements.
When our GPS gear goes a.w.o.l - not 'if' - we find ourselves in a similar pickle, but without the experience of lots of considered judgements. However, we can remedy that cheaply and easily.
We can sharpen up our DR skills to a high order, and quite quickly.
Try this - when next on an easy coastal or offshore passage, run a DR plot alongside your normal 'quick and dirty' GPS plot. Work out some Courses To Steer and some EPs. Note how closly your trad chartwork compares with what the GPS says to you, then consider carefully the reasons for any differences.
Not allowing enough leeway? Tidal vector extracted a bit out? Estimate of distance run through the water not quite good enough? Rough and ready plotting? Or is it compass error that's throwing things out....?
With the benefit of instant accurate fixes giving instant feedback, we'll all be able to hone our DR skills swiftly and painlessly. Well within a season......
In days of yore, sailing masters had precious little else as 'aids to navigation' than their skills at 'Ded. Reckng.' They practised hard, and mulled over their results. Consequently, they knew much of the time what accuracy they could expect in differing conditions, and with that came confidence in their judgements.
When our GPS gear goes a.w.o.l - not 'if' - we find ourselves in a similar pickle, but without the experience of lots of considered judgements. However, we can remedy that cheaply and easily.
We can sharpen up our DR skills to a high order, and quite quickly.
Try this - when next on an easy coastal or offshore passage, run a DR plot alongside your normal 'quick and dirty' GPS plot. Work out some Courses To Steer and some EPs. Note how closly your trad chartwork compares with what the GPS says to you, then consider carefully the reasons for any differences.
Not allowing enough leeway? Tidal vector extracted a bit out? Estimate of distance run through the water not quite good enough? Rough and ready plotting? Or is it compass error that's throwing things out....?
With the benefit of instant accurate fixes giving instant feedback, we'll all be able to hone our DR skills swiftly and painlessly. Well within a season......
