Question 40 OSV01 - Master/Chief Mate - Offshore Supply Vessels

The Correct Answer is A. **Explanation for Option A (about 1 second):** Option A ("about 1 second") is correct because it accurately defines a "short blast" as specified in the International Regulations for Preventing Collisions at Sea (COLREGs) Rule 34 and the corresponding U.S. Inland Rules. Whistle signals used to convey maneuvers in head-on and/or crossing situations (such as one short blast for "I am altering my course to starboard" or two short blasts for "I am altering my course to port") must be **short blasts**. Rule 3 (Definitions) of both International and Inland Rules defines a **short blast** as a blast of about one second's duration. **Explanation for Incorrect Options:** * **B) 2 to 4 seconds:** This duration is too long for a maneuvering signal. A blast of 4 to 6 seconds (or 4 to 10 seconds, depending on the vessel size) is defined as a **prolonged blast**, which is reserved for warning signals (like leaving a dock or restricted visibility signals). * **C) 4 to 6 seconds:** This range falls within the definition of a **prolonged blast** (defined as a blast of from four to six seconds' duration). Prolonged blasts are used for warning or signaling position in restricted visibility, not for head-on or crossing maneuvering instructions. * **D) 8 to 10 seconds:** This duration is far too long for either a short or a prolonged blast and would not correspond to any standard, regulated signal under COLREGs.