Compass Mode can serve as a quick way to supplement the information your physical rangefinder provides, and can be used to help you understand the direction and distance of objects you cannot directly see.
For example, before a stalk, you can use your physical rangefinder to range the animal; then, use Compass Mode’s built-in Rangefinder to drop a Waypoint exactly where the animal is. Now, when you begin your stalk (and, likely, lose sight of the animal as you navigate undulating terrain), you have Compass Mode and your dropped Waypoint to confirm you’re taking the optimal path toward where you last saw your target.