Question 741Navigation General

70% to pass

Your vessel is on course 270°T, speed 10 knots. The apparent wind is from 10° off the port bow, speed 30 knots. From which direction is the true wind?

A 075°T
B 255°T
C 165°T
D 345°T
AI Explanation

The correct answer is B) 255°T. To determine the direction of the true wind, we need to use the relationship between the vessel's course, speed, and the apparent wind direction and speed. The true wind direction is the wind direction that would be measured if the vessel was stationary. The formula to calculate the true wind direction is: True Wind Direction = Apparent Wind Direction + Vessel's Course - 180°. In this case, the apparent wind is from 10° off the port bow, which is 270° - 10° = 260°. Adding the vessel's course of 270° and subtracting 180° gives us the true wind direction of 255°T. The other options are incorrect because they do not correctly apply the formula to determine the true wind direction.

Related Questions
Q@q.QuestionNumber:The following types of vessels are awaiting lockage on the upper Mississippi. Wh... Q@q.QuestionNumber:What should you expect when you encounter a tsunami in the open ocean? Q@q.QuestionNumber:Illustration D036NG below represents a fixed C of E lock and dam. What navigatio... Q@q.QuestionNumber:What is an advantage of the magnetic compass aboard vessels? Q@q.QuestionNumber:The Earth's irregular heating is caused by _______________.

Ready to test your knowledge?

Take a Navigation General Practice Exam
Official Resources
USCG Navigation Rules (COLREGS) 33 CFR Navigation Rules USCG National Maritime Center
← Previous All Questions Next →

Want to practice with timed exams?

Download Coast Guard Exams for the full exam experience.

Get the App