This dataset contains the Underway (UWY) data collected on Southern Surveyor voyage SS2012_v04. The voyage took place from Fremantle to Fremantle in the Indian ocean between the 11th of August to the 5th September, 2012. The vessel was in port from the 14th - 23rd August. This dataset has been processed and archived within the CSIRO Marine and Atmospheric Research Data Centre in Hobart. Additional information regarding this dataset is contained in the cruise report for this voyage and/or the data processing report. The standard Underway (=continuously recorded) dataset from a research voyage includes Navigation (NAV), Sounder, Thermosalinograph (TSG) and Meteorological (MET) data. NAV data includes GPS (Global Positioning System) measurements of latitude, longitude, ship's direction and speed. MET data includes atmospheric temperature, humidity and pressure, wind speed and direction, and incident radiation intensity. Data from "IMOS" (Integrated Marine Observing System) sensors are also included. The sensors are port and starboard radiometers and pyranometers, wind speed; rain and rainrate. Data are recorded at 5 second intervals and stored in NetCDF format. For Public Access data (.csv files, 10 sec and 5 min intervals). See "Download Public Underway data and Processing Reports" link for details.