Weems & Plath 12" Parallel Rule

This sturdy 12-inch (30.48cm) parallel rule with brushed aluminium arms is a reliable tool for plotting courses and measuring distances on nautical charts. It features an integrated protractor scale, allowing you to measure angles and bearings from any convenient meridian or compass rose.

This parallel rule is comprised of two straight edges joined by hinges, allowing them to move closer or further apart while remaining parallel. By carefully moving the rule across the chart and securely holding down the non-moving edge, you can effectively plot a course or transfer bearings with accuracy.

Features:

• 12-inch (30.48cm) length
• Brushed aluminium arms
• Polished aluminium handles
• Milled acrylic with bevelled edges
• Integrated protractor scale (Captain Fields Pattern)
• Protective plastic sleeve
• Limited Lifetime Warranty

How to Use a Parallel Rule

Place one edge of the parallel rule along your desired course or bearing on the chart. Hold this edge securely while carefully moving the other edge to a new position on the chart. This allows you to transfer lines and angles accurately, making it an essential tool for navigation and chartwork.

A History of Precision

Parallel rules have been used by navigators for centuries to draw parallel lines on charts. The earliest versions date back to the 16th century, and the design was further refined in the 19th century by Captain William Andrew Field, who added a protractor scale and compass points for easier bearing measurement.

About Weems & Plath

Founded in 1928 by Lieutenant Commander Philip Van Horn Weems, Weems & Plath has a long and distinguished history of providing sailors with high-quality nautical instruments and navigational tools. From the Weems Plotter to the Second Setting Watch, their innovations have helped shape the world of navigation.

Today, Weems & Plath continues to uphold its tradition of craftsmanship and precision, offering a wide range of navigational tools and instruments for sailors of all levels.