Re: [Paddlewise] Paddling on Instruments - part two

Craig Jungers wrote:

Another good piece on compass use.  Thanks, Craig.

> How do you lay a course? Well it's simple enough if you have a couple of
> tools. Airplane pilots use a small protractor which you lay along a course
> with the protractor over a longitude line. You can then read the true
> heading for that course from the protractor. You must then add or subtract
> variation (look at the compass rose on the chart) and then correct for
> deviation. [snip]  You could also carry a parallel rules by
> which you can transfer a course up to the compass rose on the chart and
> simply read off the magnetic heading. But doing either of these while you
> are in your cockpit on the ocean are difficult at best.

Weems and Plath sells a large-scale protractor which allows taking bearings 
directly off a chart, or drawing course lines on a chart.  I use one on 
land to accomplish those tasks, if I can prepare ahead of time.  But, on 
the water, I rely on pre-drawn lines of __magnetic__ north-south, so I can 
take bearings (and draw course lines) directly on the chart.  This avoids 
the necessity to correct for variation.

This works for me because I cut my charts up into folio-size (or smaller) 
chunks, and have them laminated.  The plastic surface takes marks well, 
when dry, from fine-tipped Sharpie _permanent_ markers.  In addition, a 
little alcohol on a rag will remove the marks later, if I want to do so.

Laminated charts eliminate the need for bulky chart enclosures on deck.  I 
just slip the required chart under my deck bungees; when wet, the adhesion 
to the deck is very good.  One of my sometime paddling partners punches a 
hole in a corner of her assembly of laminated chart chunks, and runs a 
binder ring through the holes, clipping the entire thing to a deck line. 
This worked well for her until the ring got in her way and she just slipped 
it under the deck lines; it got sloshed off, and she lost her _entire_ 
batch of charts for a week-long trip.  We traded chart info for Nutella ... 
and the extortion was quite successful!

-- 
Dave Kruger
Astoria, OR
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