Multibeam data collected by the R/V Tangaroa along the Macquarie Ridge, which extends 1400 km southwest New Zealand. The ridge is one of a small number of ridges that interrupt the flow of the Antarctic Circumpolar Current (ACC), the world’s largest current and the dominant feature in the circulation in the Southern Ocean. The ridge constrains the flow of the ACC to gaps in the ridge, allowing for a comprehensive measurement of both its mean flow and the mesoscale variability. The voyage represented a collaboration between scientists and projects at NIWA and CSIRO Division of Marine and Atmospheric Research, the Antarctic Climate and Ecosystems Cooperative Research Centre (ACECRC), and the Research School of Earth Sciences, Australian National University (ANU) in Australia, and the Geological Nuclear Sciences Institute (GNS) in New Zealand. Voyage objectives: 1. Retrieve moorings deployed in 2007 in the gaps in the Macquarie Ridge 2. Undertake a physical oceanographic survey of the Macquarie Ridge 3. Collect sediment cores along the axis of the Macquarie Ridge and in the Emerald Basin 4. Survey the biodiversity and habitat of seamounts associated with the Macquarie Ridge 5. Deploy Argo floats