Under what condition can a deviation be made from an approved track line in restricted waters?

A deviation from an approved track line in restricted waters is permitted only if it is directed by the Commanding Officer (CO) and carried out while on the bridge. This is essential for maintaining safety and operational integrity in environments where navigation is particularly constrained. The CO is responsible for ensuring the safe operation of the vessel, and their direct involvement helps mitigate risks associated with navigating in restricted waters.

In such conditions, the CO's authority ensures that any deviation is made with full consideration of the current operational environment and potential hazards. This also promotes coordinated decision-making and clear communication among the crew. The requirement for the deviation to occur on the bridge further emphasizes the importance of real-time situational awareness and control when navigating through restricted waters, ensuring that decisions are made with all relevant information available.

The other choices do not inherently provide the authority or context required to justify a deviation from a track line in these sensitive environments. Weather changes might necessitate adjustments, but without the CO’s directive, those adjustments wouldn't be officially sanctioned. Radiotelephone communication is crucial for coordination and safety, but it must be in response to direction from the CO to be valid for deviation. Finally, the mere absence of other vessels does not eliminate the need for cautious navigation or justify an uns