Hover or tap underlined Spanish terms to see their translation and exam tip.
Nuestra embarcación está en la oposición de los faros de Cabo Trafalgar y Punta de Gracia y se obtiene en ese momento una demora de aguja de Cabo Trafalgar= 290º y una demora de aguja de Barbate= 353º. ¿Cuál será la situación en aquel instante?On the opposition line of Cape Trafalgar and Punta de Gracia lighthouses, you simultaneously take compass bearings Da Cape Trafalgar = 290º and Da Barbate = 353º. What is your position?
Show the answer
Correct answer: a) 36º 08.2' N; 005º 55.4' W.
Why it is correct
On the Cape Trafalgar–Punta de Gracia opposition, true bearing to Trafalgar is Dv = 297º, so Ct = 297º − 290º = +7º. Thus true bearing to Barbate is Dv = 353º + 7º = 000º (meridian 005º 55.4′ W), intersecting the opposition at 36º 08.2′ N, 005º 55.4′ W.
Why the others are not
- b) Does not match the intersection of the Trafalgar–Gracia opposition with the Barbate meridian (Dv = 000º).
- c) Does not match the intersection of the Trafalgar–Gracia opposition with the Barbate meridian (Dv = 000º).
- d) Does not match the intersection of the Trafalgar–Gracia opposition with the Barbate meridian (Dv = 000º).
How to work it out in the exam
- Find Ct = 297º − 290º = +7º and correct Dv(Barbate) = 353º + 7º = 000º.
- Intersect the Trafalgar–Punta de Gracia opposition with due south of Barbate: 36º 08.2′ N, 005º 55.4′ W.
Where this question comes from
- Ministerio de Transportes (Madrid) · 2023 · Convocatoria de abril · PER Test 1 · question 44 Official paper · Official answer key
- Ministerio de Transportes (Madrid) · 2023 · Convocatoria de abril · PER Test 3 · question 42 Official paper · Official answer key
Try it: Navigation calculations
Pending instructor review. Machine translation, not reviewed.