the weather gage for carrier operations. American carriers were upwind of the Japanese carriers. Every time an American aircraft carrier conducted flight operations, they opened the range to the Japanese fleet. Japanese carriers could conduct flight operations while closing the range to the American fleet. The concept of weather gage is still useful in modern yacht racing, although the term is rarely used. The sails of a boat disrupt the wind to leeward; this disruption is often called "dirt" or "dirty air". An overtaking boat on a downwind course can position itself to focus its dirty air on the boat ahead of it. Conversely, a boat on an upwind course may find itself trapped in the dirty air of a boat immediately to windward. Right-of-way rules give priority to the leeward boat and can make it advantageous to be the boat without the weather gage, especially just before the start or when the boat to leeward can point higher into the wind. Weather gauge Gauge and gage are often used as alternative spellings. To the extent that there is a difference, a weather gauge can be a form of meteorological instrumentation for measuring weather quantitatively, such as a rain gauge, thermometer, anemometer, or barometer. A gage is a challenge, and hence an entry into battle, though the word is more commonly embedded in the word engage. References Nautical terminology