33 CFR §149.570

1. (a)Each platform, single point mooring, or submerged turret loading (STL) that protrudes above the water or is marked by a buoy must display the name of the deepwater port and the name or number identifying the structure, so that the information is visible:
   1. (1)From the water at all angles of approach to the structure; and
   2. (2)From aircraft on approach to the structure if the structure is equipped with a helicopter pad.
2. (b)The information required in paragraph (a) of this section must be displayed in numbers and letters that are:
   1. (1)At least 12 inches high;
   2. (2)In vertical block style; and
   3. (3)Displayed against a contrasting background.
3. (c)If an STL protrudes from the water, it must be properly illuminated in accordance with § 149.540 of this part.