15-inch Parallel Rule | Professional Marine Navigation Binnacle

The Navigator’s Classic: 15-inch Parallel Rule

Precision meets tradition with our 15-inch Parallel Rule. A staple on every bridge and in every nav-station, this instrument is designed for mariners who demand unwavering accuracy when plotting courses, bearings, and transfer lines.

Whether you are "walking" a line from a compass rose or plotting a GPS fix on a paper chart, this rule provides the tactile stability required for professional-grade navigation.

What is the advantage of a 15-inch parallel rule?The 15-inch size is the industry standard. It is long enough to cover significant distances on a chart but compact enough to be stored easily and used in smaller chart-table spaces.

Can this be used for RYA and ASA courses?Yes. While many students start with a Portland Plotter, learning to use parallel rules is a core skill for advanced coastal navigation and offshore certifications.

Key Features & Benefits

• Optimal Length: At 15 inches, it provides the perfect balance between reach and maneuverability for standard coastal and offshore charts.

• High-Stability Links: Equipped with sturdy brushed aluminum links (or high-tension brass, depending on the specific model) to ensure the two blades remain perfectly parallel during movement.

• Superior Clarity: Crafted from high-quality, transparent acrylic with beveled edges, allowing for a clear view of chart details and symbols underneath.

• Anti-Slip Grip: Features integrated finger studs/handles designed for a secure grip, preventing the rule from sliding while you're calculating your next heading.

• Protective Finish: Engineered to resist the corrosive effects of salt air and high-humidity marine environments.

Why Choose Parallel Rules? Unlike plotters, parallel rules allow a navigator to move a course line across the entire chart surface without losing the angle, making them indispensable for large-scale route planning.