Question 40 ONC02 - Second Mate/Third Mate Unlimited Tonnage

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 mandated by the International Regulations for Preventing Collisions at Sea (COLREGs) Rule 34 (Maneuvering and Warning Signals) and the Inland Navigation Rules. * **COLREGs Rule 32(b)** defines a short blast as a blast of about one second's duration. * **Head-on and/or crossing maneuvering signals** (e.g., "I am altering my course to starboard," "I intend to overtake you on your starboard side," etc., and their equivalents in Inland Rules) are exclusively signaled using short blasts (one, two, or three short blasts). **Explanation of Why Other Options Are Incorrect:** * **Option B (2 to 4 seconds):** This duration describes a **prolonged blast**. Prolonged blasts are used for warning signals (Rule 34(d) – nearing a bend or leaving a berth) and sound signals in restricted visibility (Rule 35), not for maneuvering signals in head-on or crossing situations. * **Option C (4 to 6 seconds):** This duration is significantly longer than any standard signal defined by COLREGs or Inland Rules. It exceeds the definition of both a short blast (approx. 1 second) and a prolonged blast (4 to 6 seconds, though COLREGs Rule 32(c) simply defines it as 4 to 6 seconds). * **Option D (8 to 10 seconds):** This duration is far too long for maritime signaling. Such a lengthy blast would be confusing and does not correspond to any prescribed maneuvering or warning signal.