Question 36 RVR02 - Master of LT 500-1600 GRT

The Correct Answer is A. **Explanation for Option A (about 1 second):** Option A ("about 1 second") is correct because it accurately describes the duration of a **short blast** as defined by both the International Regulations for Preventing Collisions at Sea (COLREGs, Rule 34) and the Inland Navigation Rules (33 CFR Part 83.34). * **Definition of a Short Blast:** A short blast is defined as a blast of about one second's duration. * **Application in Head-On and Crossing Situations (Maneuvering and Warning Signals):** Whistle signals used to indicate maneuver intention (e.g., "I am turning to starboard," "I am turning to port," "I am operating astern propulsion") in head-on and crossing situations utilize short blasts (one, two, or three short blasts). Therefore, the duration of each individual blast in these signals must be about one second. **Explanation for Incorrect Options:** * **B) 2 to 4 seconds:** This duration range does not correspond to any standard, defined whistle signal blast. A **prolonged blast** is defined as 4 to 6 seconds, making 2 to 4 seconds too long for a short blast and too short for a prolonged blast. * **C) 4 to 6 seconds:** This duration defines a **prolonged blast** (COLREGs/Inland Rule 32). Prolonged blasts are used for signaling departure/arrival, restricted visibility signals (fog signals), and sometimes for warning/danger signals, but they are generally not the standardized duration for the individual blasts used in the maneuvering signals (head-on/crossing situations) listed in Rule 34. * **D) 8 to 10 seconds:** This duration is excessively long and does not correspond to any official maneuvering or warning signal blast defined in the navigation rules.