Key benefits Clear and easy to read scale marks support precise chart work and reduce reader error when plotting courses. Durable marine construction with solid arms designed to withstand the rigors of sea conditions. Large 17inch length provides stable, accurate measurement of distances and chart angles for reliable navigation planning. Professionalgrade tool favored by professionals, captains, enthusiasts and marine students for routine navigation tasks. Simple to integrate into standard chart work for voyage planning and chart verification. Product overview 17 inch parallel ruler for marine navigation with solid arms designed for durability and long service life. Enables precise measurement of distances and angles on nautical charts. Built to support clear, dependable chart work in a variety of marine environments. Intended for professional use as well as training and navigation practice. Specifications and attributes Length: 17 inches Type: parallel ruler for marine navigation Purpose: measure distance and angle on charts with stable, accurate performance Construction: solid arms designed for durability in marine settings Audience: professionals, captains, enthusiasts and marine students 23 practical use scenarios On deck voyage planning: use the parallel ruler to measure distances between waypoints on a chart and to determine angles for course plotting, ensuring planning accuracy even in dynamic conditions. Navigation training and education: students and enthusiasts practice reading scales, measuring chart distances, and determining angles to build proficiency in chart work. Prevoyage chart verification: captains and professional users verify and crosscheck chart features before departure to support safe navigation planning. Notes This description maintains the product's emphasis on function, size, durability and professional usability, focusing on the 17inch parallel ruler's role in measuring distances and chart angles for marine navigation.