Dear fellow MARMAMers, The MMO Range Finding app which I posted a while back is now available for Android devices. Many thanks to those who provided feedback and requested this option. There will also be an iOS update later this week and I'll try and make a short video demonstration so people are clear on its use and limitations. Please let me know if you've any queries. Thanks, James Google Play Store Link; https://play.google.com/store/apps/details?id=appinventor.ai_keating_marine.... Apple App Store Link; https://appsto.re/au/PRVblb.i Marine Mammal Observers mitigate for the potential impact of sound exposure on marine fauna during seismic surveys, UXO clearance or civil engineering projects. A fundamental function of the observer is to calculate the distance of an animal to the source of noise irrespective of their own position and recommend actions based on specified mitigation zones around the source of the sound. Depending on the survey type and in-water configuration, MMOs can be located 100's of metres from the centre of the source. This creates time-consuming complications when estimating where the animal is in relation to the mitigation zone. This app calculates the distance from the animal (Target) to the origin of the sound (Source) using a trigonometric cosine function. The user simply enters the distance and bearing to the Target and Source from their observation position and the app calculates the rest. James Keating, PhD Marine Ecological Consultant Perth, Western Australia +61 (0) 47 5075340 keating.marine@gmail.com