18" Aluminum Arms Parallel Rule #138

18 x 2.6 inches, ISBN: 721002001382



The 18-inch (45.72cm) Aluminum Arms Parallel Rule feature aluminum arms that join two clear acrylic rulers inscribed with a protractor scale. An essential item in any proper navigation kit, these rules are used to plot direction on a nautical chart from any convenient meridian or compass rose. The two straight-edged rules are connected to maintain the same angle. By walking the rules across the chart and securely holding down the non-moving rule, you can effectively plot a course.

  • 18-inches (45.72cm) long
  • Protractor scale
  • Sturdy clear acrylic with aluminum arms
  • Protective plastic sleeve
  • Lifetime warranty


18 x 2.6 inches
ISBN: 721002001382
Weems & Plath
Date Added:
April 2021

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