In 2009 & 2010, a team of SCUBA divers from the Reef Life Survey program circumnavigated Australia by land, collecting baseline biodiversity data on the condition of more than 500 reef sites, spanning the full Australian coastline and the diverse inshore marine ecosystems found along it. Since that first ‘Lap of Aus’, the condition of Australia’s marine environment has declined in many locations, potentially as a result of a variety of human pressures, such as climate change, exploitation, pollution, coastal development, introduced species and land runoff. These changes are, however, occurring out-of-sight. Which of these pressures are having the greatest impacts, and the full extent of change across Australia’s unique marine ecosystems is not understood. While the Reef Life Survey program has continued to collect biodiversity data over the last decade from primary monitoring locations across Australia, the ‘Mapping Change in Inshore Ecosystems Around Australia’ project has allowed a concerted effort towards a comprehensive resurvey of reef sites spanning the continent, to assess change at sites first surveyed in the 2009 & 2010 ‘Lap of Aus’. The project has directly enabled the engagement of 94 skilled SCUBA divers acting in a voluntary capacity, to collect detailed and standardised data on environmental condition at 681 sites. The information has directly fed into a national assessment of reef biodiversity for the State of the Environment report, an assessment of population trends for >1000 marine species, online interactive indicator reports and distribution maps and images of >2,000 reef species found in Australian waters.