Marina Exam for OIC: When can an officer of the watch deviate from the Rules of Road?

Marina Exam for OIC

When can an officer of the watch deviate from the Rules of Road? 

A. To avoid immediate danger. 
B. Never 
C. When the bearing of the vessel does not appreciably change. 
D. Only if there is risk of collision. 

Answer:  A. To avoid immediate danger.