What must you obtain permission for from the CO in the yards?

Obtaining permission from the Commanding Officer (CO) in the yards is primarily associated with specific activities that pose significant risks or require careful coordination. This includes actions that involve divers, use of cofferdams, firefighting equipment, managing flooding risks, and starting or stopping mains. The complexity and potential hazards associated with these tasks necessitate explicit approval to ensure safety and compliance with operational protocols.

When it comes to tasks like starting machinery, performing routine maintenance, or using cleaning solvents, these typically fall within the standard operating procedures that trained personnel can manage without the need for direct CO permission. These activities are generally covered by established processes emphasizing safety and responsibility, allowing workers to perform them under defined conditions without needing higher-level authorization. Hence, the correct emphasis here is on the need for permission for activities that could significantly affect the safety and operational integrity of a facility, making option C the appropriate choice.