Parallel Rule — Captain Fields 600 mm

📐 Extra-Long Precision • Professional Chart Navigation • Built for Serious Plotting

The Captain Fields 600 mm Parallel Rule is designed for navigators who want maximum reach, stability, and accuracy when working on paper charts. With its extended length and precise parallel motion, this is a professional-grade instrument for skippers, instructors, and students who value traditional chartwork and dependable manual navigation.

Manufactured to exacting standards by Captain Fields, this 600 mm rule is ideal for large charts and long course transfers where shorter rules require multiple repositionings.

🧭 Why the 600 mm Parallel Rule Makes a Difference

📏 Extra-Long 600 mm Length — Fewer Moves, Greater Accuracy

• 600 mm working length spans a larger portion of standard and large-format charts

• Reduces the need for repeated repositioning when transferring bearings

• Improves accuracy by minimising cumulative alignment errors

For passage planning and offshore chartwork, the longer length is a clear advantage.

🔁 True Parallel Motion for Reliable Bearings

• Precision twin-arm parallel linkage keeps the working edges perfectly parallel throughout movement

• Allows accurate transfer of bearings from the compass rose to the course line

• Maintains alignment across multiple shifts—essential for safe navigation

This consistency is what makes parallel rules a trusted navigation tool.

👁️ Clear Visibility & High-Contrast Markings

• Transparent acrylic construction keeps chart detail visible at all times

• Bold graduations and edge markings aid clean, confident line work

• Reduced parallax improves plotting precision

You see exactly what you’re doing—nothing is obscured.

🛠️ Built for Daily Use

• Made from rigid, durable acrylic that resists flexing

• Smooth, polished edges glide easily over charts without snagging

• Designed to withstand repeated use in training rooms, chart tables, and nav stations

This is a working instrument, not a disposable accessory.

⚓ Essential for Traditional Navigation

Even with modern electronics, parallel rules remain fundamental for:

• Passage planning and course checks

• Teaching navigation principles

• Redundant manual plotting when electronics fail

• Maintaining core seamanship skills

The 600 mm length is particularly valued in instructional and professional environments.

📐 Specifications

• 📏 Length: 600 mm

• 📐 Type: Twin-arm parallel rule

• 🧭 Function: Bearing transfer & course plotting

• 🛠️ Material: Clear acrylic

• ⚓ Use: Nautical chart navigation, training, professional chartwork

🎯 Who This Is For

• ⚓ Skippers & offshore sailors — long, accurate course transfers

• 🧭 Navigation instructors & students — classroom-ready precision

• 🚢 Commercial & professional mariners — dependable chart-table equipment

• 🗺️ Traditional navigators — those who value disciplined seamanship

• 🎁 Maritime gift buyers — a practical, professional navigation tool

⭐ Why Choose Captain Fields?

Captain Fields navigation instruments are trusted for clarity, accuracy, and durability. Designed for real chartwork, they support both learning and professional navigation with no unnecessary complexity.

The 600 mm Parallel Rule embodies that philosophy: long reach, precise motion, and confidence in every line you draw.

Plot longer courses with fewer moves

Add the Captain Fields 600 mm Parallel Rule to your chart kit and enjoy smoother, more accurate navigation on every chart.
Add to cart and keep your chartwork precise and professional.