In restricted visibility the speed of a vessel without operational radar may be（）enable effective avoiding action to be taken on sighting another ship.

单项选择题In restricted visibility a towed vessel must sound a fog signal when it is（）.

A.the last vessel in the tow
B.the last vessel in the tow and it is carrying a crew
C.manned，regardless of its position in the tow
D.None of the above are correct

单项选择题In reduced visibility，you hear two prolonged blasts of a whistle. This signal is sounded by a （）.

A.power-driven vessel dead in the water
B.sailing vessel on the port tack
C.vessel not under command
D.vessel fishing with nets

单项选择题In order to maintain speed while changing course from a close reach to a broad reach，the sails should be（）.

A.lowered
B.reefed
C.hauled in
D.eased out

单项选择题In order for a vessel to be engaged in fishing she must be（）.

A.underway
B.using gear which extends more than 50 meters outboard
C.using a seine of some type
D.using gear which restricts her maneuverability

单项选择题In fog you observe your radar and determine that risk of collision exists with a vessel which is 2 miles off your port bow. You should（）.

A.stop your engines
B.sound the danger signal at two-minute intervals
C.hold course and speed until the other vessel is sighted
D.take avoiding action as soon as possible