CAVU. Ceiling and Visibility Unlimited. The acronym appears on aviation weather reports and in pilot lore as shorthand for the perfect flying day: clear skies, no haze, horizons that stretch forever. The term entered common usage in the 1930s and remains standard meteorological terminology today. For instrument-rated pilots, CAVU is more than a forecast—it is an aspiration. On such days, visual navigation becomes effortless, terrain features reveal themselves from miles away, and the airplane seems to perform better simply because the pilot can see. George H.W. Bush, a Navy pilot in World War II, had a small bronze plaque engraved with "CAVU" hanging at his home in Kennebunkport, Maine. It was, he explained in a letter to his children, the kind of day he wished for everyone.