17inch parallel ruler designed for stable, precise measurement of distances and angles on nautical charts. It provides reliable plotting performance to support accurate navigation decisions. Clear scale marks and easytoread layout help you interpret chart information quickly, reducing errors and speeding up plotting even in demanding conditions. Solidarm construction delivers durable, longlasting performance suitable for daily marine use and the rigors of nautical work. Targeted for professionals, captains, hobbyists, and marine students who need a dependable navigation tool to improve chart work and course planning. Sized for practical chart plotting: 17inch length to work with standard marine charts, with robust construction that stands up to deck use and frequent handling. Practical use scenarios: Plot a course between two known positions on a nautical chart with accurate distance and bearing measurements. Determine angular distances and bearings between chart features for route planning. Use in training environments to teach distance and bearing measurement and reinforce chartreading skills.