What is the mnemonic for correcting for east or west variation?

The correct mnemonic for correcting for east or west variation is "East is least and West is best." This phrase helps pilots remember how to adjust for magnetic variation when converting between true and magnetic headings. When navigating, it's important to know that if you are adjusting a true heading to account for east variation, you should subtract this variation because it is "least." Conversely, if you are traveling in a region where there is west variation, you need to add this variation to your heading since it is considered "best" to compensate for the westward difference.

This mnemonic helps provide a quick and effective way to remember the necessary adjustments without having to perform complex calculations on the fly. It reinforces the directionality of magnetic variation, making it easier for pilots to ensure they are flying the correct course.

The other choices either present incorrect or less clear messages regarding how to handle variation. They do not provide the precise reminder needed for adjustments in a straightforward manner like the chosen phrase does.