Coastal Skipper and Yachtmaster Quiz · Chartwork and passage planning
You are making a night landfall on this light, charted with a range of 18M. Tonight the visibility is about 2 miles. At what distance should you expect to pick it up?
Night at sea in haze. A lighthouse on a headland to the right shows a white light. A chart label reads Fl 10s 35m 18M. The dark outline of a yacht is on the left. Caption: visibility tonight, about 2 miles, in haze.
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Much less than 18 miles: the charted range assumes visibility of 10 miles. The range on the chart is the nominal range: how far the light is seen when the meteorological visibility is 10 miles. In haze it is picked up much closer (a luminous range diagram gives the figure), though a powerful light is still seen further off than unlit objects. Plan the landfall on the reduced range, and remember that height of eye limits it too.
