The Blue Fly Challenge is about the fly, not the delivery system. Western fly tackle or spinning tackle would be fine, as long as the fish are caught with a fly that is predominantly blue and uses the TenkaraBum Blue Fly Yarn as one of the materials. A Mepps spinner with a blue yarn roostertail would not qualify. A blue woolly bugger cast with a threadline spinning rod would qualify, as would a blue fly fished behind a casting bubble.