Hover or tap underlined Spanish terms to see their translation and exam tip.
Navegando desde el faro de Punta Tarifa con Rumbo al faro de Punta Cires, sabiendo que el valor de la declinación magnética es 4ºNW y el Desvío 3ºW. ¿Qué Rumbo de aguja llevamos?Sailing directly from Punta Tarifa lighthouse towards Punta Cires lighthouse with magnetic variation 4º NW and deviation 3º W, what compass course are you steering?
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Correct answer: d) 138.5º
Why it is correct
The charted true course from Isla de Tarifa lighthouse (36º 00.0′ N, 005º 36.6′ W) to Punta Cires lighthouse (35º 54.7′ N, 005º 28.8′ W) is Rv = 131.5º. With Ct = −4º − 3º = −7º, the compass course is Ra = 131.5º − (−7º) = 138.5º.
Why the others are not
- a) Does not subtract total compass error Ct = −7º from true course Rv = 131.5º.
- b) Does not subtract total compass error Ct = −7º from true course Rv = 131.5º.
- c) Does not subtract total compass error Ct = −7º from true course Rv = 131.5º.
How to work it out in the exam
- Measure on the chart the true course from Isla de Tarifa to Punta Cires: Rv = 131.5º.
- With Ct = −4º − 3º = −7º, compute Ra = 131.5º + 7º = 138.5º.
Where this question comes from
- Ministerio de Transportes (Madrid) · 2020 · Convocatoria de diciembre · PER Test 5 · question 42 Official paper · Official answer key
Try it: Navigation calculations
Pending instructor review. Machine translation, not reviewed.