Navigation lights

See 'Prevention Of Collisions At Sea Regs1983' (home/library/rules and regulations)

• Rule 27 - Vessel Not Under Command
• COLREG 1972 Annex 1, Section 9 (b) reads:
  • (i)All round lights shall be so located as not to be obscured by masts, topmasts or superstructures within angular sectors of more than 6°, except anchor lights prescribed in Rule 30, which need not to be placed at an impractical height above the hull.
  • (ii) If it is impractical to comply with paragraph (b)(i) of this section by exhibiting only one all-round light, two all-round lights shall be used suitably positioned or screened so that they appear, as far as practicable, as one light at the distance of one mile.