Using A Compass In Overcast Conditions — Best Techniques?

Preparing for Overcast Conditions

Before heading out in overcast weather, familiarize yourself with your compass and its settings. Ensure you have the correct declination for your location, which is the difference between magnetic north and true north. In the United States, declination varies by region, but for example, in 2023, the declination in New York is around 17 degrees east, while in California it’s around 18 degrees west. Adjust your compass accordingly to get accurate readings. This step is crucial for ensuring your map and compass are aligned.

Orienting Your Map and Taking Bearings

To use your compass in overcast conditions, first, orient your map with the compass needle. Hold the compass level and adjust the direction-of-travel arrow until it aligns with the magnetic needle. This will set the declination and ensure your map is correctly oriented. Next, use the compass to take bearings by aligning the direction-of-travel arrow with a known landmark or your intended route. Take note of the bearing and use it to navigate. Repeat this process at regular intervals to ensure you stay on course.

Navigating by Triangulation

Triangulation involves using at least two known points to determine your location. In overcast conditions, use landmarks and known locations to create a mental or physical map of your surroundings. By taking bearings from these points, you can create a triangle of reference. This method is particularly effective in areas with distinctive landmarks or features. For example, if you know the location of two mountains and your intended campsite, you can use the compass to take bearings from each mountain to determine your location and course. This technique requires attention to detail and a good understanding of compass use but can be highly effective in overcast conditions.