Map Rulers for a Certain Women's Four-Wheel Drive Navigation Rally

If you're navigating a multi-day, all-women's four-wheel drive rally through the American West — one with roadbooks and checkpoints, paper maps and compasses, and absolutely no GPS — this is the page for you. It's a rally, not a race (they're particular about that, and rightly so). We'd love to call it by name, but we don't have permission to use it yet. You know what you're here for.

The rally hands you maps at 1:25,000, 1:50,000, 1:100,000, and 1:200,000 scale, and your coordinates come as latitude and longitude. Below are three ways to gear up, from off-the-shelf to fully tuned for the course.

Option 1 — Stock Map Rulers

Our standard map rulers cover all four rally scales. Each one plots latitude/longitude coordinates (minutes/seconds on one edge, decimal minutes on the other), handles UTM/MGRS as a bonus, and measures distance in miles and meters on the back. Proven tools, in stock, ready to ship.

One thing to know: a stock ruler's coordinate scale is spaced for latitude. Minutes of longitude are shorter than minutes of latitude (more on that below), so when you measure longitude you angle the ruler across the map until its endpoints line up with the graticule. It works well — navigators have done it this way for a century — but it's an extra step every time you plot.

1:25,000 Scale Map Ruler Scales: 1:25,000 x 2.5 minutes
1:50,000 Scale Map Ruler Scales: 1:50,000 x 5 minutes
1:100,000 Scale Map Ruler Scales: 1:100,000 x 10 minutes
1:200,000 Scale Map Ruler Scales: 1:200,000 x 15 minutes

Why a Latitude-Adjusted Longitude Scale?

Minutes of latitude are the same size everywhere: one minute is one nautical mile, about 1,852 meters. Minutes of longitude shrink as you leave the equator — at the latitudes this rally runs, a minute of longitude is only about 76–85% as wide as a minute of latitude. That's why a single ruler edge can't read both directly, and why stock rulers get angled for longitude measurements.

A custom ruler fixes this with a second scale: one edge for latitude, and a separate longitude edge compressed by exactly the right amount for a chosen latitude. At that design latitude you lay the ruler flat along the map's parallels and read longitude directly — no angling, no geometry, no wondering whether you slipped. When you're tired, dusty, and the clock is running, plotting a fix in half the time with fewer mistakes is a real advantage.

The catch: the longitude scale is exact only at its design latitude. Move away from it and a small error creeps in — so you either angle the ruler a little (much less than with a stock ruler), or you carry rulers tuned for each stretch of the course. That's exactly the difference between the two custom options below.

Option 2 — Budget: Custom Rulers Tuned to 32°

All four rally scales as custom rulers, each with a longitude scale adjusted for 32° north — the southern end of the course. Degrees and decimal minutes, just like your roadbook coordinates, with miles and kilometers on the back. Near 32° they read longitude dead-on with the ruler held flat; as you work north you angle the ruler slightly — noticeably less than a stock ruler needs.

The pre-built 32° collection is being prepared — check back shortly, or contact us and we'll let you know when it's ready.

Option 3 — Deluxe: Rulers for the Whole Course, 32°–40°

The full-course treatment: for each scale, a set of rulers with a matched latitude/longitude pair for every degree of latitude from 32° to 40°. Wherever the day's route takes you, flip to the ruler face for your current latitude and plot with the ruler flat on the map. You're never more than half a degree from a perfectly tuned longitude scale, which means virtually no angling, ever.

Budget vs. deluxe in one sentence: the 32° rulers are exact at the south end of the course and need a little angling as you move north; the full-course sets are exact everywhere the rally goes.

The pre-built full-course collection is being prepared — check back shortly, or contact us and we'll let you know when it's ready.

A Few Practical Notes

Copying a collection takes a free customer account — the copies land in My Designs, where you can open each one in the designer.
Prefer to start from scratch? The custom ruler designer and the ruler set builder are open to everyone.
New to plotting latitude and longitude? Start with our lat/lon quick guide and the plotting video.
Ordering for a whole team? Get in touch — we're happy to help with team orders.