1929 Travel Air 4000 Sunset Snuggler flight loitering over the beach waiting for the last rays of sun is rewarded with a green flash. They occur when a sharp ocean horizon rises to block the sun (the sun doesn't set remember--the earth rises) and sunlight is defracted into a raibow of colors. Low level haze absorbs all but the green part of the spectrum. No tease to trick visitors, green flashes really do occur although rarely. If you're lucky enough to see one from a biplane you might even see several if you climb quickly and conditions cooperate as you watch the sun set (earth rise) again. You'll even get to see the sun rise in the west!