The provided context is insufficient to fully explain how to use a rotating compass bezel for navigation. It only references a compass being used to determine south by comparing the hour hand to the 12:00 mark. A complete answer requires a more detailed explanation of using the rotating bezel, also known as the compass rose, for setting a bearing and navigating. Therefore, I will provide a general overview and instructions based on common compass usage.
Understanding the Compass Bezel
The rotating bezel on a compass, often called the compass rose, is a critical tool for navigation. It's marked with degrees (0-360) and sometimes cardinal directions (N, S, E, W). Its primary function is to help you set and follow a bearing.
Steps for Using a Rotating Compass Bezel
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Orient the Compass: Hold the compass flat in your hand. Wait for the needle to settle. The red (or marked) end of the needle points to magnetic north.
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Determine Your Desired Bearing: A bearing is the direction you want to travel, expressed in degrees. You can find this on a map or by observing a distant landmark. For example, let's say you want to travel on a bearing of 90 degrees (East).
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Rotate the Bezel: Rotate the bezel until the desired bearing (e.g., 90 degrees) aligns with the direction-of-travel arrow (usually marked on the compass housing or baseplate). Some compasses have a marking for this; others require you to mentally align the degree marking with the direction arrow.
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Align the Compass with Magnetic North: Now, keeping the bezel fixed, rotate your body and the compass together until the red (north) end of the compass needle aligns with the north marking on the bezel. It's crucial to align the needle with the bezel's north marking, not the physical housing's markings.
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Follow Your Bearing: Once the needle and bezel are aligned with North, the direction-of-travel arrow on your compass points in the direction of your desired bearing. Pick a landmark in that direction and walk towards it. Check your compass regularly to maintain your course.
Back Bearings
You can also use the bezel to determine a back bearing, which is the reciprocal direction to your current heading. For example, if you're heading due east (90 degrees), your back bearing is west (270 degrees). This is useful for retracing your steps. To set a back bearing, rotate the bezel 180 degrees from your forward bearing. So, if your direction-of-travel arrow points to 90 degrees, rotate the bezel so it points to 270 degrees. Follow the process in steps 4 and 5.
Declination
Magnetic declination is the angular difference between true north (geographic north) and magnetic north. It varies depending on your location. For precise navigation, you need to account for declination. Some compasses allow you to adjust for declination directly on the bezel. If yours does, consult the compass manual or a map for your area's declination and adjust the bezel accordingly before taking bearings. If your compass doesn't have declination adjustment, you'll need to manually add or subtract the declination from your bearings (depending on whether it's east or west declination).
Example
Let's say you want to travel at a bearing of 45 degrees (northeast).
- Rotate the bezel until 45 degrees aligns with the direction-of-travel arrow.
- Hold the compass flat and rotate your body until the red end of the needle aligns with the North marking on the bezel.
- The direction-of-travel arrow now points in the direction of 45 degrees.
