A pilot vessel on pilotage duty shall show identity lights （）.

单项选择题A pilot vessel on pilotage duty at night will show sidelights and a sternlight （）.

A.when at anchor
B.only when making way
C.at any time when underway
D.only when the identifying lights are not being shown

单项选择题A pilot vessel may continue to sound an identity signal if she is （）.

A.underway，but not making way
B.aground
C.being towed
D.not engaged in pilotage duty

单项选择题A navigator fixing a vessel’s position by radar （）.

A.should never use radar bearings
B.should only use radar bearings when the range exceeds the distance to the horizon
C.can use radar information from one object to fix the position
D.must use information from targets forward of the beam

单项选择题A line of position derived by radar range from an identified point on a coast will be a(n) （）.

A.straight line
B.arc
C.parabola
D.line parallel to the coast

单项选择题A head on situation shall be deemed to exist at night when a power-driven vessel sees another power-driven vessel ahead and （）.

A.one sidelight and the masthead light are visible
B.the vessels will pass closer than half a mile
C.both vessels sound one prolonged blast
D.both sidelights and masthead light(s) are visible