A non-invasive, rapid, accurate, and affordable technique to measure the size of surface-feeding reef manta raysusing small drones. The drones are also very useful in determining the sex and maturity of reef manta rays. Importantly, all of these were undertaken with minimal and limited impact tothis vulnerable species.Choose your favourite poster to win the People's Choice Award at the 2021 SGS Research Showcase: https://auckland.au1.qualtrics.com/jfe/form/SV_9Fw8Omf43pstYUu