Question 4930 Deck General

The correct answer is B) I am operating astern propulsion. The visual signal of the code letter "S" (Sierra) displayed by an icebreaker assisting a vessel through an ice field signifies that the icebreaker is operating astern propulsion. This is in accordance with the International Code of Signals, which specifies the meaning of various visual signals used for communication between ships. The other answer choices are incorrect because they do not accurately represent the meaning of the "S" (Sierra) signal in this context. The icebreaker is not altering its course to port (A) or starboard (D), nor is it stopped and making no way through the water (C). The key function of an icebreaker in this scenario is to provide propulsive assistance to the vessel by operating in reverse, which is signified by the "S" (Sierra) signal.