Raise hand upward to the full extent of the arm, palm to the front. Hold that position until the signal is understood.
One of eleven standard hand signals adopted by the American Society of Agricultural and Biological Engineers (ASABE). This video is used for the Hispanic version of the National Safe Tractor and Machinery Operation Program (NSTMOP), www.NSTMOP.psu.edu, and in the AgSafety4U program.
More Agricultural safety videos can be found on eXtension's AgSafety4u Youtube channel: https://www.youtube.com/user/AgSafety4u/videos