Hover or tap underlined Spanish terms to see their translation and exam tip.
Navegando a 4 nudos por la Ría de Vigo, dejamos de notar el viento aparente (viento aparente igual a 0 nudos), esto significa que:Sailing at 4 knots through the Ría de Vigo, we stop feeling any apparent wind (apparent wind = 0 knots). This means that:
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Correct answer: c) There is a true wind dead astern of 4 knots.
Why it is correct
When running dead before a true wind equal to our boat speed (4 knots), the true wind (+4) and the headway wind (−4) cancel out and the apparent wind drops to zero.
Why the others are not
- a) With 4 knots of true wind ahead we would feel 8 knots of apparent wind.
- b) If true wind were zero, we would feel 4 knots on the bow from our headway.
- d) It becomes zero when running dead downwind at the speed of the true wind.
How to work it out in the exam
- Zero apparent wind at 4 kn boat speed = 4 kn true wind dead astern.
Where this question comes from
- Ministerio de Transportes (Madrid) · 2020 · Convocatoria de diciembre · PER Test 5 · question 36 Official paper · Official answer key
Pending instructor review. Machine translation, not reviewed.