RE: [Paddlewise] Dead Reckoning Accuracy

PeterO said: 

 
> It was the first time most of us had tried ded reckoning. 
> Things I think could improve my accuracy are: -
> 
> 1. Select bearings which were likely to be clearly defined 
> i.e large objects such as points, light houses, water towers, 
>  with high contrast in the line of sight. A point covered in 
> trees against a backdrop of a coast covered in trees was one 
> of the poor selections I made, it was almost invisible in fact.
> 2. Take a hard surface on which to put the map for plotting 
> bearings, if possible do most of the plotting in advance at 
> home 3. Use a portland square rather than protractor and setsquare.
> 4. If using laminated maps take a fine water proof pen (and 
> some alcohol as an erasor).
> 5. The theory looked easy, putting it into practice on the 
> water was hard.
> 6. Work out in advance which direction to paddle if bearings 
> aren't quite right.

Peter,

All excellent ideas. I personally prefer to use a map and compass only while
on the water and do most of the route planning and back-up planning before I
get in the boat. It's real hard to use a divider or compass in a moving
boat. I usually just use my thumb for distance measurements and a calibrated
eyeball together with a finger or hand to get bearings.

I learned the hard way to always carry a GPS. Last year I organized a 14
mile roundtrip coastal paddle. We launched and landed at our 1/2 way point
in beautiful typical Southern California weather. After having brunch at a
beachside restaurant, we went back to the boats to find fog so thick that
you couldn't see more than 20-30 feet in front of you, and fairly large
surf.

After launching and searching for 45 minutes for one missing paddler
(compass washed off of the boat, broke a paddle returning to the
beach--spare was carried by his son already on the water), until the CG
notified us by radio, that the paddler was on the beach--at least he used
his head and phoned them), we had a stressful paddle back to our launch
site.

It was disconcerting to measure distance off of the shore by the sound of
breaking waves, not being able to see more than one or two other paddlers,
and not being able to identify the beach we launched from because the
shoreline was invisible. As a result, I almost always have the GPS with me
now, I just don't use it for the majority of my navigation and never as my
sole navigational aid.

BTW, a friend showed me that he just writes all of his waypoints, bearings,
etc on the front deck of his glass boat with a permanent marker. Acetone
seems to take it off fairly easily. Even though my boat is not new, I'm not
sure if I'm ready to try this yet.

All the best,

Steve Holtzman
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