Under the rules for attending a cargo tank during loading or unloading, which of the following is NOT one of the required qualifications of the person watching?

AAMVA CDL Manual Sec 9.5.2 (nhcdm.pdf p.9-13); 49 CFR 177.834

These attendance requirements exist so that if a leak, spill, or fire starts during loading or unloading, someone capable of recognizing the danger and acting, including moving the vehicle, is right there instead of discovering the problem minutes later from across the yard. A momentary lapse, stepping away, being distracted, or not knowing the emergency procedure, defeats the entire purpose of requiring an attendant in the first place.