Which of the following is not a responsibility of the Chief Mate?

The Chief Mate, also known as the First Mate, plays a critical role in the management of the ship's day-to-day operations, particularly regarding the deck crew and the overall safety of the vessel. While the Chief Mate is responsible for training the crew in safety practices, ensuring compliance with maritime laws and regulations, and managing deck operations effectively, they do not typically engage in engine room maintenance.

Engine room maintenance falls under the purview of the Chief Engineer and their team, who are specially trained to handle the complexities of the ship’s machinery and systems. This delineation of duties is crucial for the efficient functioning of the ship’s operations, as it allows each officer to focus on their specific areas of expertise. Thus, the responsibility of conducting engine room maintenance does not align with the Chief Mate's role, confirming why this option is correct.