From the mid-1970s he worked on excavations in Berkshire, Hampshire, Dorset, Wiltshire and the Isle of Wight for the Department of the Environment (DOE). In 1979 the archaeological section of the DOE for the region became Wessex Archaeology, a non-profit organisation which is one of the biggest archaeological practices in the country. He continues to work for Wessex Archaeology when not filming. Harding has been a member of the Institute of Field Archaeologists since 1985, and in 2006 was elected a Fellow of the Society of Antiquaries of London. On 24 July 2008 he received an honorary doctorate from the University of Southampton in archaeology. As a qualified SCUBA diver he is the president of the Nautical Archaeology Society, a Portsmouth-based charity formed to further interest in nautical cultural heritage.