Donaukanal is a concrete serpent that doubles as Vienna’s largest public art gallery. We trace the emergence of a collective coalition of artists, plant whisperers, and drone pilots who engage in a long established space for international outdoor art. Kanal Opal is the gemstone to be harvested out of aerosol ephemerality, small artistic interventions at the edge of urban art and the techno-poetics of drone-enabled activism are part of an externalization process that puts the works of the one decade old Science Visualization Lab of the University of Applied Arts into new perspectives.