Airblasts were monitored at four coal strip mines and at a limestone quarry. Instrumentation selection and use are described. Data analysis includes an assessment of the predictability of peak overpressures by means of the cube root scaled distance law. Predictability for the cases studied is not good. A computer program was written to simulate airblasts induced by multiple-hole blasts. A series of small experimental blasts were detonated and monitored to allow an assessment of the program. It is clear that airblasts, especially when induced by very small charges and monitored at very close distances, are highly sensitive to detonation times. Retrofitting of airblast records occasionally was possible, but considerably improved fieldwork is required to validate or refute the computer model.