单项选择题
A.on each watch，immediately before being relieved
B.before embarking on a voyage of more than 24 hours
C.daily，at 1200 local zone time
D.weekly，before 0000 Sunday
单项选择题 The owner or Master of a towing vessel shall ensure that all tests and inspections of gear take place and are logged（）.
单项选择题 The irregular black line around a charted light such as Race Rock Light indicates that it is （）.
单项选择题 The horizontal flat surfaces where the upper stock joins the rudder are the（）.