How is the dangerous semicircle around a moving LP system determined?

Master the Navigation, Seamanship, and Shiphandling (NSS) – Officer of the Deck (OOD) Phase 2 Exam with engaging flashcards and multiple choice questions, complete with hints and explanations. Prepare comprehensively for your test!

Multiple Choice

How is the dangerous semicircle around a moving LP system determined?

When a moving low-pressure system passes, its wind field isn’t the same in all directions. To judge danger, split the system along the line of its track. In the Northern Hemisphere, winds around a low rotate counterclockwise, and the forward motion of the system adds to the winds on the front-right quadrant. That forward-right semicircle tends to have the strongest winds and seas, making it dangerous. The opposite semicircle, on the left side relative to the track, is the navigable area. So the navigable side is the left, while the right-hand side ahead of the track is the dangerous one. (Note: in the Southern Hemisphere, rotation is opposite, so the dangerous semicircle would be forward-left.)

When a moving low-pressure system passes, its wind field isn’t the same in all directions. To judge danger, split the system along the line of its track. In the Northern Hemisphere, winds around a low rotate counterclockwise, and the forward motion of the system adds to the winds on the front-right quadrant. That forward-right semicircle tends to have the strongest winds and seas, making it dangerous. The opposite semicircle, on the left side relative to the track, is the navigable area. So the navigable side is the left, while the right-hand side ahead of the track is the dangerous one. (Note: in the Southern Hemisphere, rotation is opposite, so the dangerous semicircle would be forward-left.)

More practice questions