Question 40 OSV02 - 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 defines a **short blast** of the whistle, as specified in the International Regulations for Preventing Collisions at Sea (COLREGs) Rule 34 (Maneuvering and Warning Signals) and the equivalent Inland Rules. * **COLREGs Rule 34(a)(i):** When vessels are in sight of one another, a power-driven vessel undertaking a maneuver (such as head-on or crossing) shall indicate that maneuver by the following signals: "One short blast to mean 'I am altering my course to starboard.'" * **COLREGs Rule 32(b) Definition:** A "short blast" is a blast of about one second's duration. These signals are mandatory for indicating intent in maneuvering situations (head-on, crossing, overtaking) where risk of collision exists. **Explanation for Why Other Options are Incorrect:** * **B) 2 to 4 seconds:** This duration falls between a short blast (1 second) and a prolonged blast (4 to 6 seconds). It does not correspond to a standard defined signal used for maneuvering intent in head-on or crossing situations under COLREGs/Inland Rules. * **C) 4 to 6 seconds:** This duration defines a **prolonged blast** (COLREGs Rule 32(b): a blast of from four to six seconds' duration). Prolonged blasts are used primarily for warning signals (Rule 34(d)) or restricted visibility signals (Rule 35), not for indicating maneuvering intent (turn to starboard/port, astern propulsion) in head-on or crossing situations. * **D) 8 to 10 seconds:** This duration significantly exceeds the definition of both a short blast (1 second) and a prolonged blast (4 to 6 seconds) and does not correspond to any official defined blast signal in COLREGs or Inland Rules.