Abstract: An automatic inflatable structure deflation system has a cover panel that is detachable attached over a deflation opening in the wall of the inflatable structure. The cover panel is pull away from the inflatable structure by a deflation line extending from the cover panel to a tie-down element in the event that the inflatable structure is displaced. The deflation opening is relatively large to enable quick deflation of the inflatable structure. A deflation opening may have a deflation opening area ratio, or area of the opening to the volume of air within the inflatable structure of 0.01 cm2/cc or more. A deflation opening may have a length of 25 cm or more. The cover panel is sealed to the inflatable structure by a seal feature such as a hook-and-loop fastener and/or a press-seal feature.