| What it is | Magnetic compass on a clear ruled plate |
| Key parts | Needle, rotating bezel, travel arrow |
| Look for | Adjustable declination |
| Why | Map navigation; no batteries |
A baseplate compass mounts a rotating magnetic needle and bezel on a flat, transparent plate marked with rulers and direction-of-travel arrow, designed for taking and following bearings off a map. Its declination adjustment and clear base make it the standard navigation compass for hikers and mountaineers — and a Ten Essentials item that never needs batteries.
Why carry one
It’s how you take a bearing on a topographic map; pick one with declination adjustment. A core Ten Essentials item.
Frequently asked questions
What is a baseplate compass?
A baseplate compass is a navigation compass built on a flat, clear plastic base with straight edges and rulers, a rotating bezel marked in degrees, and a direction-of-travel arrow. The transparent base lets you lay it on a map to take bearings — making it far more useful for navigation than a simple button compass.
Why should a baseplate compass have declination adjustment?
Because magnetic north differs from true (map) north by an amount called declination that varies by location. A compass with built-in declination adjustment lets you set this once so every bearing you take is automatically corrected, removing a common and potentially serious source of navigation error.
Do you still need a compass if you have GPS?
Yes — a compass needs no batteries or signal and can't fail electronically, so it's a Ten Essentials backup that works when a GPS dies, breaks, or loses reception. Skilled navigators carry both: GPS for convenience and a map and compass as the reliable fallback.
Sources
- Compass features — The Mountaineers
- Navigation gear — American Hiking Society