Sea Fishing and Sea Angling Online: Portland GPS Plotter 

Portland GPS Plotter
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Mike Thrussell on 01 January, 2006 08:55:00
 
This is a simple and cracking idea that saves time and makes the plotting of  a
latitude and longitude GPS chart positions dead easy.
It's basically a clear acrylic see through parallel ruler, but the separate 
rules open flat away from each other without crabbing sideways as normal 
parallel rulers do.
To use the plotter, place the closed rule alongside the Longitude line of the 
chart with the base of the rulers overhanging the Longitude scale. There are 
holes drilled along the edge of the rules. Place the hole next to the required 
Longitude coordinate. Now slide the second rule across the chart until the 
outside edge reaches the latitude coordinate required. Make a small vertical 
line with a pencil down the outside edge of the rule. Now place the pencil 
inside the corresponding hole near to the line you've just drawn and pull the 
pencil and ruler across the vertical line to draw a cross. The junction of the 
two lines is your GPS position.
To  measure the Latitude and Longitude of a mark or waypoint align one hole and
 ruler edge with the object. Square the plotter with a nearby chart grid line. 
Now read the Longitude. Walk the ruler sideways across the chart until it meets
 the latitude bar and read off the coordinate opposite the corresponding hole in
 the ruler edge.
The plotter is very well made and obviously designed to take the rigours of 
the marine cabin environment. Its dimensions are 16ins long by 3ins closed, but
 it expands in width to 9ins. It retails for £29.95.
It is available from all good chandlers, but for your nearest stockists 
contact by e-mail sales@blundellharling.co.uk.  Blundell Harling, Lynch Lane,
Weymouth, Dorset DT4 9DW Tel: 01305  206000.