A common problem for monitoring programs is a lag between collecting and disseminating results. Here, the authors show that the visual assessment of hard coral cover can provide a timely, generally reliable estimate, broadly comparable with values derived from photo-transect surveys, with known relative bias. Photo-quadrat analysis is critical in cases where a more detailed appraisal of habitat composition at finer taxonomic level is necessary and when time and resources permit. A benefit of conducting rapid visual assessments in addition to the photo-quadrat surveys is that the visual estimates are instantly available. Visual estimates of encrusting algae, and particularly fleshy macroalgae and turf algae estimates were not in as close agreement with the photo-quadrat estimates, highlighting the importance of improved and more rigorous training of observers. It is highly desirable for observer errors to be reduced as much as possible through improved training and the regular assessment of inter-observer variability.
