Doubtless many a navigator arrives at an erroneous fix due to the erratic effects of refraction. Seldom, however, is he in a position to get a careful check on the error caused by refraction. A unique opportunity offered itself to nail the lie of the false horizon on March 6, 1933, as the destroyer force stood out of San Diego Harbor. Some one noted that the Coronado Islands resembled an aircraft carrier in company with several smaller ships. This unusual condition resulted from a peculiar mirage along the sea horizon. The sea was calm with light airs from the north, temperature 64°F., sky clear, with a fringe of smoke and haze 1 high along the horizon. A forest fire raged about SO miles north of Coronado and the smoke from it spread along the horizon from north to west and southwest.
Speaking of Horizons
By Lieutenant Commander P. V. H. Weems, U. S. Navy (Retired)