Question 54 OSV01 - Master/Chief Mate - Offshore Supply Vessels

The Correct Answer is C The signal described—the code letter "S" (Sierra) displayed visually, typically by lights or flags, especially in the context of an icebreaker assisting a vessel—is defined by the International Regulations for Preventing Collisions at Sea (COLREGs), specifically rules or associated signals dealing with maneuvering. **Explanation for C (I am operating astern propulsion):** The single-letter sound or light signal "S" (Sierra) is designated in maritime signaling codes (often referenced in COLREGs Annex III or related specialized maneuvering signals, though its primary origin is the International Code of Signals) as the signal for **"I am operating astern propulsion."** When an icebreaker displays this signal while maneuvering in close quarters (such as breaking ice channels), it warns the assisted vessel that the icebreaker is moving backward or using reverse thrust, which is critical information for the vessel following closely behind. **Explanation of Why Other Options Are Incorrect:** * **A) My vessel is stopped and making no way through the water:** The signal for a vessel stopped and making no way is typically the single-letter code "Q" (Quebec) or specific light signals (such as two all-around red lights in a vertical line for a vessel constrained by her draft, or specific signals indicating anchoring/aground), not "S". * **B) I am altering my course to port:** The signal for "I am altering my course to port" is typically the single-letter code "E" (Echo) or, in COLREGs Rule 34, two short blasts when using sound signals (or specific maneuvering lights if applicable). "S" is not used for a port turn. * **D) I am altering my course to starboard:** The signal for "I am altering my course to starboard" is typically the single-letter code "I" (India) or, in COLREGs Rule 34, one short blast when using sound signals (or specific maneuvering lights if applicable). "S" is not used for a starboard turn.