Parallel Rules and Triangles Weems & Plath Navigator's Parallel Rules Navigator's Parallel Rules are inscribed with full 180o protractor markings.  The middle of the bottom edge forms the protractor center when the arms are closed to combine the essential features of a protractor plotter and a basic parallel ruler.  Allows courses to be measured from a convenient meridian.  Extra strong, crystal-clear acrylic.  Available in five sizes: 21" Commercial Rule, 0.25" arm thickness, rigid metal arms and handles 18" Rule, 0.19" arm thickness, aluminum arms and handles 15" Rule, 0.22" arm thickness, brushed aluminum arms and handles 15" Rule, 0.14" arm thickness, solid brass arms and handles  12" Rule, 0.22" arm thickness, brushed aluminum arms and handles Weems & Plath Parallel Rules These traditional parallel rules do not have protractor markings.  Two sizes: 12" Rule, 0.22" arm thickness, brushed aluminum arms and handles 15" Rule, 0.12" arm thickness, aluminum arms and handles Weems & Plath Triple Parallel Rule A new release of an old piloting favorite.  Three 12" rules allow greater parallel walk without the diagonal creep associated with traditional designs.  Milled with beveled edges, 0.19" arm thickness, aluminum arms and handles.   Weems and Plath Protractor Triangles Using two 45o triangles provides an easy method of plotting and performing other chart work.  With colored, high-contrast protractor scales, the triangle can be easily aligned in any direction with a chart meridian.  Direction is maintained as one triangle slides along the other to the desired position.  Clear vinylite, 0.08" thick; short sides 7-1/2".  Available with or without handles.   Ordering Information: 121777 24" Navigator's Parallel Rule $36.90   122145 18" Navigator's Parallel Rule $24.30   122144 15" Navigator's Parallel Rule, Aluminum Arms $16.65   122143 15" Navigator's Parallel Rule, Brass Arms $33.75   122141 12" Navigator's Parallel Rule $15.75   122142 12" Parallel Rule, No Gradations $13.50   122261 15" Value Parallel Rule, No Gradations $11.70   122256 Triple Parallel Rule $19.35   122169 Protractor Triangle Without Handle $10.80   122170 Protractor Triangle With Handle $12.60     Select other navigation tools: Navigation Tool Sets Plotting Tools Parallel Rules, Triangles, and Square Protractors Dividers and Compasses Nautical Slide Rules and Calculators Navigation Plotting Sheets and Reusable Plotting Boards Chart Lights, Chart Cases, Magnifiers, and Nav Tool Storage Binoculars