单项选择题
A.The master may，at his/her discretion，turn off the AIS if he/she believes that it may compromise the safety or security of the vessel
B.Under no circumstances shall AIS be turned off while underway as this could endanger the vessel and those around her
C.AIS is always required to be operating if the vessel is in or in the vicinity of a VTS area
D.AIS is always required to be operating if the vessel is within 100 nautical miles of the coastline
单项选择题 Which of the following statements is TRUE regarding automatic identification systems (AIS)? （）
单项选择题 Which information must automatic identification systems (AIS) automatically provide to appropriately equipped shore stations，vessels and aircraft? （）
单项选择题 When should the emergency position-indicating radiobeacon be activated after abandoning a ship?（）