(a) Each light under part 149, subpart E of this chapter, used as a navigation aid on a deepwater port, must be lit continuously from sunset to sunrise.
(b) During construction, a platform or single point mooring, if positioned on the surface or within the net under keel depth for tankers transiting within the safety zone, must be marked with at least one of the following:
(1) The obstruction lights required for the structure in part 149, subpart E of this chapter;
(2) The fixed lights of a vessel attending the structure; or
(3) The general illumination lights on the structure, if they meet or exceed the intensity required for obstruction lights required for the structure.
(c) The focal plane of each obstruction light and lit rotating beacon must always coincide with the horizontal plane that passes through the light source.