Mapping is the first step in understanding where different animals live on the seafloor and is essential to the management of marine parks. This is the first episode in a series of five videos from the Seamount Corals Survey 2018, a month long voyage on CSIRO Investigator to map and survey deep-sea coral reefs across an area of underwater seamounts south of Tasmania. The voyage criss-crossed many seamounts in and near the Huon and Tasman Fracture marine parks, which are home to both pristine and previously fished coral reefs. These two parks are part of a larger network of Australian Marine Parks that surround Australia’s coastline and protect our offshore marine environment.