单项选择题
A.danger B.vessels are excluded from the area C.the buoy is a mooring buoy D.operating restrictions are in effect
A white buoy with a blue band is（）.A.an isolated danger...
单项选择题A white buoy with a blue band is（）.
A.an isolated danger mark B.a hydrographic data collection buoy C.a mooring buoy D.marking a restricted area
A V-shaped ripple with the point of the V pointing upst...
单项选择题A V-shaped ripple with the point of the V pointing upstream in a river may indicate a（）.
A.submerged rock，not dangerous to navigation B.sunken wreck，not dangerous to navigation C.towed-under buoy D.All of the above
A vessel is（）when she is not at anchor，made fast to the...
单项选择题A vessel is（）when she is not at anchor，made fast to the shore，or aground.
A.underway B.making way C.dead in the water D.a power driven vessel
