What is the exemption for a power-driven vessel between 12 and 20 meters in length regarding Rule 23(a)(i) and (ii)?

Power-driven vessels between 12 and 20 meters in length benefit from specific exemptions under the International Regulations for Preventing Collisions at Sea (COLREGs), particularly in regard to the lighting requirements outlined in Rule 23. When operating, these vessels are required to exhibit lights that aid in their visibility. However, there is an important exemption that allows them to meet minimal requirements if they display a white light aft that is visible all around the horizon.

This exemption is significant because it helps to streamline the requirement for smaller vessels without compromising safety. The requirement for the white light ensures that they are still identifiable as power-driven vessels and not sailing or fishing vessels, which must exhibit different lights or a more complex arrangement. The presence of this light allows these vessels greater maneuverability while maintaining compliance with international regulations.

The other options involve requirements that do not apply to this particular exemption. For example, while red and green sidelights or specific masthead lighting may apply to other categories of vessels or lengths, they do not reflect the unique provisions for vessels in this size range under Rule 23(a)(i) and (ii). The simple requirement for a visible white light aft underscores the balance between ensuring visibility and facilitating operation for smaller power-driven vessels.