Abstract: A method for controlling timing error in the firing of an idle seismic air gun comprises the steps of identifying an acceptable range of seismic air gun timing error, and identifying a relationship between seismic air gun timing error and an idle period preceding a seismic air gun firing event. The first firing event time following an idle period is then compensated according to the identified relationship to control the timing error within the identified acceptable range. The invention may be implemented using computer means such as machine-readable storage media. The invention may be applied to advantage when air gun firing delays are experienced, such as during selective changes from one air gun group to another air gun group for purposes of achieving a desired center-of-source position.