The true course from point A to point B is 317°. A SSW wind causes a 4° leeway, variation is 6°W and deviation is 1°E. What is the magnetic compass course to steer to make good the true course?
• Leeway: how wind from SSW will affect your heading relative to your desired track of 317°T • Order of applying corrections: leeway, variation, then deviation when going from true course to compass course • Remember the saying for variation/deviation: "True Virgins Make Dull Company" or similar, and how to step through T–M–C
• Start with 317°T. Should you apply the 4° leeway to the left or right, given the wind is from SSW and you want to make good 317°? Sketch the situation on a small compass rose. • When you have the course after leeway, convert True → Magnetic using 6°W variation. Does a westerly variation make magnetic larger or smaller than true? • Finally apply the 1°E deviation to go Magnetic → Compass. Does an easterly deviation make the compass course larger or smaller than magnetic?
• Be clear on whether leeway is added or subtracted from the intended true course when the wind is from the left or right. • Check the direction of each correction step: you are going from True to Compass, not the other way around. • After each step (leeway, variation, deviation), pause and ask: "Should this number be getting bigger or smaller with this sign of variation/deviation?"
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