Alfredo Contaldovideo
5.1.1 - 1 Chart Problem Solving 🗺️ Nautical License Over 12 Miles ⚓
October 2, 2026 · 8 min · 2K views · Capo della Vita, Elba
What this video covers
Nautical chart problem 5.1.1-1 on chart 5D, sector A is solved step by step as a current triangle exercise for the Italian unlimited nautical license exam.0:06 The vessel Daphne starts at GPS position 42°51'N, 010°16.9'E and must reach point B, located on a true bearing of 127° from the Capo della Vita monument at 2.9 nautical miles, in exactly 30 minutes.0:54 A southerly current of 180° at 2 knots is present.1:01 Because the current vector drawn at full scale lands on shore, the entire diagram is halved: the current is plotted at 1 knot, the route vector covers half the distance, and the velocity triangle is constructed at the 30-minute scale throughout.3:29 Measuring the propulsive speed leg of the triangle on the latitude scale yields 5 miles, which doubles to 10 knots — confirmed by the arithmetic check (5 miles ÷ 0.5 hours = 10 knots) and within the exam tolerance band of 9–11 knots.6:36 When a current vector plots on land, halving the entire velocity triangle keeps the diagram at sea without changing the result.3:54
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