Aerial surveys are widely used to assess the abundance and distribution of marine mammals, traditionally relying on human observers. Image-based detection has been increasingly applied, offering advantages such as improved precision and accuracy, enhanced safety, and verifiable records of sightings. Dugongs (Dugong dugon) have been monitored using aerial surveys along the coast of Queensland since the 1980s. However, differences in detection rates between observer- and image-based platforms, and the influence of environmental conditions on detection, must be understood to support this transition. Data for this study were drawn from 2022 dugong population surveys conducted across the southern Great Barrier Reef, Hervey Bay, and Moreton Bay, which employed both aerial observers and cameras mounted beneath the plane. To compare dugong counts across platforms and assess the effects of environmental variables on detection, we used generalised linear mixed modelling. Although mean sightings per transect were higher in imagery (11.19 ± 20.1) than observer data (7.75 ± 7.31), dugong counts did not significantly differ between platforms. Our analysis did not detect trends associating detection rates with turbidity, glare, or sea state. These findings suggest imagery surveys provide comparable dugong detection outcomes to human observers, supporting the transition to image-based approaches for dugong monitoring.