What is the maximum vessel length that allows for lights installation exemption?

The correct answer indicates that vessels less than 20 meters in length are exempt from the requirement to display certain navigation lights. This exemption is based on the understanding that smaller vessels often have less complex operations and are typically operated in environments where visibility and navigation requirements differ from larger craft. Therefore, not imposing the same lighting requirements on small vessels can reduce the burden on operators without significantly increasing safety risks. This regulation is crucial because it allows for greater flexibility and encourages participation by smaller vessel operators while still acknowledging the need for basic safety and visibility considerations.

The other options suggest different lengths, but they exceed the 20-meter threshold where these exemptions apply. By establishing a limit at 20 meters, maritime regulations aim to balance safety with operational practicality, ensuring that the rules remain effective and appropriate for vessels of various sizes.