... every 20 secondsSeaplane head onGreenRedFigure 5. 42 Seaplane lights. 124 Seamanship Techniques JUDGING ANOTHER VESSEL’S HEADING AT NIGHTWe know that the arc of a sidelight shows over 1 12 ... may be exhibitedFigure 5 .27 Pilot vessel engaged on pilotage duty.Sources of reference: Rules 21 , 22 , 29 , 30, 35(i) and Annex 1.Single white all-round light,range 2 miles, shown whereit can ... asabove 119 Preventing Collisions at SeaRange of visibility Luminous intensity of(luminous range) of light in candelas forlight in nautical miles K = 0.8DI1 0.9 2 4.33 12 427 5 52 694Note:...