单选题A towing vessel is tripped when（）.A it is overtaken by the towB it is pulled sideways by the towC the weight of the towing hawser causes loss of maneuverabilityD the propeller is fouled by the towing hawser

A vessel towing astern in an operation which severely restricts the towing vessel and her tow in their ability to change course shall，when making way，exhibit ______.

A.the masthead lights for a towing vessel

B.the lights for a vessel restricted in its ability to maneuver

C.sidelights，stern light and towing light

D.All of the above

There is a ______ when one or more vessels are towing or pushing another vessel or vessels，provided that they are all involved in commercial activities and not in a salvage operation．

A.private safety

B.private maritime adventure

C.common safety

D.common maritime adventure

A mobile offshore drilling unit under tow is approaching a fog bank. When should fog signals be started?

A.When the towing vessel enters the fog

B.When the drilling rig enters the fog

C.When the towing vessel can no longer be seen from the rig

D.Immediately

If practical, when shall a manned vessel being towed sound her fog signal?______.

A.Immediately before the towing vessel sounds hers

B.Immediately after the towing vessel sounds hers.

C.As close to the mid-cycle of the towing vessel’s signals as possible

D.At any time as long as the interval is correct

A vessel brought alongside should be fended off the towing vessel by ______.

A.crew members using their arms

B.crew members using the strong muscles of their legs

C.fenders

D.No fending is necessary due to the rugged construction of most towing vessels

For safety reasons，when assistance towing ______．

A.the disabled vessel should be towed to the nearest port

B.the disabled vessel should be inspected for flammable gases

C.passengers should always be removed from the disabled vessel

D.personnel on the disabled vessel should don PFD's

A towing vessel pushing a barge ahead and rigidly connected in a composite unit shall show the lights of ______．

A.A vessel towing by pushing ahead

B.A power-driven vessel，not towing

C.A barge being pushed ahead

D.Either answer A or answer B

A tug is best positioned for towing and maneuvering on rivers and other restricted waters where wave action is limited when ______.

A.directly astern and pushing the tow

B.towing on a hawser

C.towing alongside and parallel to the vessel it is towing

D.towing on the hip

An ocean tow is sinking in deep water. Attempts to sever the towing hawser are unsuccessful Which action should now be taken?______.

A.Abandon the towing vessel.

B.Radio for emergency assistance.

C.Slip the towline and allow it to run off the drum.

D.Secure all watertight openings on the towing vessel.