This report describes scientific activities on RRS James Cook cruise 30, “ANDREX”, westwards from 30°E and in the vicinity of latitude 60°S, between late December 2008 and late January 2009. The cruise was terminated about halfway through by a medical emergency. Hydrographic work comprised 27 CTD/LADCP stations. Water samples were captured for measurement of salinity, dissolved oxygen, inorganic nutrients, oxygen isotope fraction, chlorofluorocarbons and sulphur hexafluoride, dissolved inorganic carbon and alkalinity, helium / tritium / noble gases and radiocarbon. Underway measurements comprised navigation, currents (ADCP), meteorology, and sea surface temperature and salinity. The remainder of the hydrographic section was executed a year later on RRS James Clark Ross, cruise JR239
