SfM appears to be a great, cost-effective, means of 3D reef mapping and your article nicely outlines the process, but you fail to cite a recent article that has already applied it to coral reefs (Leon, JX, Roelfsema, CM, Saunders, MI, Phinn, SR. 2015. Measuring coral reef terrain roughness using 'Structure-from-Motion' close-range photogrammetry. Geomorphology 242:21-28, DOI:10.1016/j.geomorph.2015.01.030) A quick search reveals an earlier article, not cited in your article or Leon et al.'s: Hu He, Ferrari R, McKinnon D, Roff, G, Smith R, Upcroft, B. 2012. Measuring reef complexity and rugosity from monocular video bathymetric reconstruction. Proceedings of the 12th International Coral Reef Symposium, Cairns, Australia, 9-13 July 2012. Disappointing.