单项选择题
A.mine clearance operation B.towing operation C.dredging or surveying or underwater operation D.fishing
A vessel aground would show the same dayshape as a（）.A....
单项选择题A vessel aground would show the same dayshape as a（）.
A.vessel towing a submerged object B.dredge underway and dredging C.hydrographic survey vessel at anchor and surveying D.None of the above
A survey (special purpose mark) buoy（）.A.must be lighte...
单项选择题A survey (special purpose mark) buoy（）.
A.must be lighted B.may have a flashing red light C.may have a fixed white light D.None of the above
A gas-free certificate would usually be issued by a(n)（...
单项选择题A gas-free certificate would usually be issued by a(n)（）.
A.CCS marine surveyor B.certified marine chemist C.port engineer D.MSA marine inspector
