Question 45 ONC04 - Mate of LT 500-1600 GRT

The Correct Answer is B **Explanation for Option B (One prolonged blast) being correct:** According to the International Regulations for Preventing Collisions at Sea (COLREGs) and the U.S. Inland Navigation Rules (which often mirror COLREGs for maneuvering signals), Rule 34(e) specifically addresses signals when approaching a bend or obstruction: * **Rule 34(e):** "A vessel nearing a bend or an area of a channel or fairway where other vessels may be obscured by an intervening obstruction shall sound **one prolonged blast**." * This signal serves as a warning to any vessel that may be approaching from the other side of the bend, alerting them to the vessel's presence before sight is possible. **Explanation of why other options are incorrect:** * **A) One short blast:** This signal is defined as "I am altering my course to starboard" when vessels are in sight of one another (Rule 34(a)(i)). It is a maneuvering signal, not an obstruction warning signal. * **C) Two short blasts:** This signal is defined as "I am altering my course to port" when vessels are in sight of one another (Rule 34(a)(ii)). Like one short blast, it is a maneuvering signal, not an obstruction warning. * **D) One long blast:** While "prolonged" and "long" are sometimes used interchangeably in informal speech, the official regulatory term specified in COLREGs for this warning signal is "one **prolonged** blast" (a blast of 4 to 6 seconds). The term "long blast" is typically reserved in regulations for use in restricted visibility (Rule 35) or as a general danger signal (Rule 34(d) uses 'at least five short and rapid blasts' for danger, not one long blast). Therefore, **prolonged blast** is the precise and correct regulatory term required for approaching a bend.