This spell functions as [_air walk_](/spells/air-walk), except you can rise no higher than 1 foot off the ground, you cannot pass over liquid, and the air you walk on is less stable than solid ground. When walking on air, you ignore difficult terrain that is less than 1 foot high, you do not trigger effects based on weight (such as a pressure plate), and any creature trying to track you through areas you crossed with this spell takes a –10 penalty on its Perception or Survival check to do so. However, because of the instability of the air you walk on, your speed is reduced by 10 feet (to a minimum of 5 feet) and you take a –4 penalty on Acrobatics, Climb, and Ride checks. If you have 1 rank in Fly, your speed is not reduced when using this spell, and you can cross over liquid at half speed. If you have 5 ranks in Fly, you can cross liquid at full speed and do not take the penalties to your skill checks.