Johann R. E. Lutjeharms, South Africa's leading physical oceanographer, died at the age of 67 at his home in Stellenbosch on World Oceans Day, 8 June 2011, after a 10-year battle with a complicated form of cancer. His work was central in the process of enlightening the oceanographic and climate system community to the global importance of the complex, energetic, eddy-rich environment of the Agulhas Current. He aptly referred to this current system, including the transfer of Indian Ocean water into the South Atlantic, as the “Greater Agulhas System.” Johann was born on 13 April 1944 in Bloemfontein, South Africa, where he attended Grey College. At the University of Cape Town (UCT), he completed his bachelor's degree in physics followed by a M.Sc. (cum laude) in oceanography in 1971. His work there led to his first research article (on the variability of the water movement in the southwest Indian Ocean), which appeared in Nature. Many papers would follow, covering a broad range of aspects of the oceans around South Africa. His curriculum vitae lists 177 articles published in peer-reviewed international journals, many of them in AGU's Journal of Geophysical Research (JGR) and Geophysical Research Letters, including his most frequently cited ones.