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6.5 Declination

The magnetic reference for Earth is north regardless of whether you are traveling north or south. Magnetic declination, or declination, is the difference between the true north reading from the map and the magnetic north reading from a compass. When a compass is used in combination with a map, a correction must be made to allow for declination.

In North America, magnetic declination varies from 30 degrees East in Alaska to 20 degrees West in Labrador, Maine. The degrees of declination for an area are usually located on the bottom margin of the map near the north arrow, or they can be located using a declination chart.declination over the CONUS

The method for correcting for declination is as follows:
1. For Easterly Declination, subtract the declination from the true reading to obtain the magnetic reading. Magnetic = true - easterly declination
2. For Westerly Declination, add the declination to the true reading to obtain the magnetic reading. Magnetic = true + westerly declination

An easy way to remember whether to add or subtract is "West is best and East is least." So for West declination, add to the true reading (West is best, and therefore a larger number) and for East declination subtract from the true reading (East is least, and therefore a smaller number).West is best and east is least

Example 1 - Paloma is in San Jose, California. The declination is 17°E. Paloma's compass reading from her current location to the mountain range to which she is traveling is 35°. What is her true reading?

Step 1. The declination of 17°E is an easterly declination.

Step 2. In this case, True - east = magnetic according to the "East is least" guideline above, so we will solve the equation for the true reading and find that true = magnetic + east. We must add the declination to go from the magnetic reading on the compass to the true reading.

East is least

Paloma's true reading is 52 degrees.

Example 2 - Sonia is in Augusta, Maine. She has a compass with a magnetic north reading of 45°. What is her true reading on a map?

Step 1. Look up the declination for Augusta, Maine, on a declination chart. Maine has a declination of 18°W.

Step 2. Because 18°W is a westerly declination, remember "West is best" and that the magnetic = true + west. In this case, to solve for the true reading, we must subtract the declination from the magnetic bearing: true = magnetic - west.

west is best

Sonia's true reading is 27 degrees.

When traveling in an opposite direction and adjusting map readings for use with compass readings, do the opposite of the above for adding and subtracting the declination. 

Example 3 - Roger looks at a map and takes an azimuth reading of 85°, a true reading, off the map from where he is standing to the location of a tower. The declination for the area is 12°E. What is the magnetic reading?

Step 1. In order to find the magnetic reading by using a compass, subtract the easterly declination. Remember, "East is least."

85° - 12°= 73°

Roger's magnetic reading is 73 degrees.

 

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Incident Position Standards and the Next Generation Position Task Books Now Available for UASD, UASM, UASL and UASP

Date: July 31, 2025
Questions?  Please contact:
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NWCG is excited to announce that Incident Position Standards and the Next Generation Position Task Books are now available for all four Unmanned Aircraft Systems positions:

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The Performance Support Packages for these positions were developed as part of the Incident Performance and Training Modernization effort. These resources support trainees, qualified personnel, and evaluators in their respective roles.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

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NWCG is excited to announce that Incident Position Standards and the Next Generation Position Task Books are now available for Radio Operator (RADO) and Incident Communications Center Manager (INCM).

The Performance Support Packages for these positions were developed as part of the Incident Performance and Training Modernization effort. These resources support trainees, qualified personnel, and evaluators in their respective roles.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

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Date: July 29, 2025
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The Equipment Technology Committee (ETC) issued Equipment Bulletin: 25-004, notifying the wildland fire community about a newly discovered invasive species and actions to take if found. Golden mussels, a highly invasive species recently identified in California, pose a significant risk to native ecosystems, infrastructure, and fire equipment. These mussels rapidly colonize hard and soft surfaces, including aquatic plants and fire equipment, clogging pipes, fouling motors, disrupting water systems, and impacting native species.

To help prevent their spread, fire personnel must follow the decontamination procedures outlined in the NWCG Guide to Preventing Aquatic Invasive Species Transport by Wildland Fire Operations, PMS 444. Additionally, report any sightings immediately to your Lead Resource Advisor and include clear, close-up photos and location details.

Read the complete ETC Equipment Bulletin: 25-004 to learn more. 

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NWCG is excited to announce that Incident Position Standards and the Next Generation Position Task Books are now available for Incident Commander Type 5 (ICT5) and Firefighter Type 1 Squad Boss (FFT1).

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Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

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