A.must utilize magnetic courses B.must take set and drift into account C.should be replotted hourly D.should be started each time the vessel's position is fixed
单项选择题A dead reckoning (DR) plot().
A.ignores the effect of surface currents B.is most useful when in sight of land C.must be plotted using magnetic courses D.may be started at an assumed position
单项选择题A cardinal mark showing an uninterrupted quick-flashing white light indicates the deepest water in the area is on the().
A.north side of the mark B.west side of the mark C.east side of the mark D.south side of the mark
单项选择题A buoy,being a shape of cylinder and with red group flashing,shows that it is().
A.left-side buoy B.right-side buoy C.a buoy of safety D.a buoy of danger
单项选择题A buoy with a composite group-flashing light indicates a(n)().
A.anchorage area B.fish net area C.bifurcation D.dredging area
单项选择题A buoy marking a wreck will show a(n)().
A.white light FL (2) and a topmark of 2 black spheres B.occulting green light and may be lettered C.yellow light and will be numbered D.continuous quick white light and may be numbered