What length of vessel qualifies for the lights repositioning exemption under COLREGs?

Vessels that are less than 50 meters in length are allowed to reposition their navigational lights according to their size and operational needs. However, the specific question pertains to the exemption related to the repositioning of lights on vessels that qualify under different lengths. According to COLREGs, vessels less than 150 meters in length have a provision allowing for certain modifications in their light positioning.

This flexibility considers the operational practicality for smaller vessels, enabling them to maintain their visibility while navigating safely. As a vessel’s length increases, the regulatory standards for lights and shapes become more stringent to ensure that larger vessels maintain a clear signal to other vessels in navigation, which is vital for collision prevention and safety on the water.

In this context, the choice regarding 150 meters aligns with the regulations, making it the correct option for this question. The other options either provide exempt lengths that do not align with the COLREGs stipulations or overshoot the established regulations regarding repositioning lights.