You depart LAT 50°06.0'N, LONG 153°06.0'E...

Question 1 of 2707066636eea28f7522a1c51b07d

You depart LAT 50°06.0'N, LONG 153°06.0'E and steam 879 miles on course 090°. What is the LONG of arrival?

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Question 1 of 27070

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You depart LAT 50°06.0'N, LONG 153°06.0'E and steam 879 miles on course 090°. What is the LONG of arrival?

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🔍 Key Concepts

• Difference of longitude (DLOX) when steaming east or west on a parallel of latitude • Using departure formula for middle latitude sailing: Departure = Distance × cosine (latitude) • Relationship between departure (in minutes of longitude) and degrees of longitude (60 NM per degree)

💭 Think About

• Since your course is 090°, are you changing latitude, longitude, or both? What does this tell you about which sailing formula to use? • How do you convert the steamed distance on an east–west course at 50°N into a change in longitude? Which trigonometric function is involved? • Once you find the change in longitude, how do you decide whether to add or subtract it from your starting longitude, and could you cross the 180° meridian on this leg?

✅ Before You Answer

• Be sure you are using cosine of the correct latitude (50°06.0'N or an approximation, depending on method) • Confirm your departure in nautical miles before converting it to minutes and then degrees of longitude (60 NM = 1° of longitude) • Check whether your final longitude should be E or W, and whether the track length is enough to cross the 180° meridian (International Date Line)