The correct answer is D) Schedules for loading cargo. When a vessel is under the control of the Naval Control of Shipping Organization, the naval authorities would not give orders about the schedules for loading cargo. This is because the Naval Control of Shipping Organization is responsible for managing the movement and routing of merchant ships, but the specific details of cargo loading are typically left to the vessel's master and crew to determine. The other options are incorrect because the naval authorities may provide orders or guidance related to rescue operations, diversions, and visual communication at sea, as these aspects fall under the purview of the Naval Control of Shipping Organization's oversight and coordination responsibilities.