We often fly with water ballast at Moriarty, and some pilots prefer to bring their gliders to the launch line with wing wheels still in place, due to venting issues. With one wing down, water leaks from the wing at a pretty fast rate on some gliders. This can cause an imbalance, so we don't mind keeping the wing level as much as possible. As a result, we do not teach tow pilots that "wings level" implies anything at all. On the other hand, if the wing runner puts the wing DOWN, that means "HOLD!" Plus, there is a two arms up (crossed or held out) to signal a halt to operations.