Question 40 ONC05 - Master or Mate of LT 200 GRT

The Correct Answer is A. **Explanation for Option A (about 1 second):** Option A, "about 1 second," is the correct duration for a short blast as defined by the International Regulations for Preventing Collisions at Sea (COLREGs) Rule 32(a) and the Inland Navigation Rules. * **Definition:** Rule 32(a) defines a **short blast** as a blast of about one second's duration. * **Application:** The maneuvering and warning signals used in head-on, crossing, and overtaking situations (such as one short blast for "I intend to leave you on my port side," or five short blasts for danger/doubt) all utilize short blasts. Therefore, the duration of each individual blast in these situations is defined as about 1 second. **Explanation for Incorrect Options:** * **B) 2 to 4 seconds:** This duration range does not correspond to any standard whistle signal defined in the rules. A "prolonged blast" (used for restricted visibility or leaving a dock/bend) is defined as 4 to 6 seconds. * **C) 4 to 6 seconds:** This is the definition of a **prolonged blast** (Rule 32(b)). Prolonged blasts are used for fog signals (Rule 35) or warning signals (Rule 34(e)), but not for the individual blasts within the maneuvering signals (short blasts) used in head-on and crossing situations. * **D) 8 to 10 seconds:** This duration is significantly longer than any whistle signal defined in the COLREGs or Inland Rules and would not be an appropriate standardized signal.