What is the primary responsibility of the CDO?

The primary responsibility of the Chief Deck Officer (CDO) is to advise, supervise, and direct the Officer of the Deck (OOD). The CDO plays a crucial role in overseeing the ship's operations, ensuring that everything runs smoothly and safely. This involves providing guidance to the OOD, who is in charge of the ship's watch and navigation, especially in complex situations or when making critical decisions. The CDO’s leadership and expertise are essential in managing day-to-day operations, navigating challenging scenarios, and upholding maritime standards.

In contrast, other roles mentioned in the options focus on specific duties that are typically not within the primary scope of the CDO. For example, navigating the ship is primarily the responsibility of the OOD, who manages the actual navigation and tactical movements. Managing crew assignments may fall under a different officer or department responsible for personnel management rather than the CDO. Lastly, maintaining the ship's maintenance log is usually entrusted to engineering or other specialized roles that handle the operational upkeep of the vessel. Thus, the CDO's role is fundamentally tied to oversight and guidance, which makes advising, supervising, and directing the OOD the most accurate characterization of their primary responsibility.