Gaathier completed his M.Sc at the Unesco Chair for Geohydrology and his PhD at the Nelson Mandela Metropolitan University. His focus has always been subsurface fluid flow. He has received extensive technical training in aspects of hydrology in Germany, Belgium, Denmark, Tunisia and Morocco, with the latter sponsored through the International Atomic Energy Agency. He has worked in gold, uranium and coal mining as well as on shale gas research.
Gaathier has served on technical panels in South Africa to help water research projects focus on sustainable development. At the Water Research Commission of South Africa, for example, he was involved in a pilot project related to geothermal energy. He was also chosen to serve on the steering comittee of the International Association of Hydrogeologists Early Career Network.
Gaathier was voted one of the Brightest Young Minds in South Africa for the year 2010. Mail and Guardian top 200 Young South Africans to take to lunch for 2011 and a World Islamic Economic Forum Global Young Fellow for 2013. He was also chosen as one of the top 50 Alumni by the BYM for the past 15 years. In the past he was awarded an Erasmus Mundus Scholarship for exchange at the Catholic University of Leuven in Belgium. He is currently a Senior Lecturer at the Mandela University and has a research interest in flow in porous media, sampling, data mining, energy and numerical modelling. Gaathier also serves as the Deputy Dean for the Faculty of Science.