Question 40 ONC07 - OUPV-Near Coastal

The Correct Answer is A. **Explanation for Option A (Correct Answer):** Option A, "about 1 second," is correct because it accurately describes the duration of a **short blast** as defined by the International Regulations for Preventing Collisions at Sea (COLREGs) and the Inland Navigation Rules. * **COLREGs Rule 32(a) and Inland Rule 32(a)** define a **short blast** as a blast of about one second's duration. * The maneuvering and warning signals used in head-on and/or crossing situations (Rules 34(a) and 34(b), and Inland Rules 34(a) and 34(b)) utilize short blasts: * One short blast ("I intend to leave you on my port side") * Two short blasts ("I intend to leave you on my starboard side") * Three short blasts ("I am operating astern propulsion") Therefore, the duration of the blast used in these situations is defined as about one second. **Explanation of Why Other Options Are Incorrect:** * **B) 2 to 4 seconds:** This duration is too long for a short blast. While a **prolonged blast** is defined as 4 to 6 seconds, 2 to 4 seconds does not correspond to a specifically defined maneuvering signal duration. * **C) 4 to 6 seconds:** This duration defines a **prolonged blast** (COLREGs Rule 32(b) and Inland Rule 32(b)). Prolonged blasts are used for signals like restricted visibility (Rule 35) or when approaching a bend or leaving a dock (Rule 34(e)), not for the basic maneuvering signals (head-on/crossing) described in the question. * **D) 8 to 10 seconds:** This duration is significantly longer than any standard whistle signal defined in the International or Inland Rules.