LIGHTS

Light stars shown on bridges represent 2F.Y(hor). In addition, all the bridges
from Tower Bridge (51°30.3N 0°04.5W) to Wandsworth Bridge (51°27.9N 0°11.3W) carry
Iso.W.2s(occas) or VQ.W(occas) lights above certain arches. These lights give
warning that vessels are approaching or navigating under the arch showing the
light and other vessels must keep clear. For further details, see Admiralty
Sailing Directions.
Light stars without legends represent two fixed lights displayed vertically.
They are seen as red to port and green to starboard when proceeding upriver.