Stellenbosch University
Welcome to Stellenbosch University
From mathematics to building ocean wave prediction models in New Zealand
Author: Laura van Laeren (Faculty of Science: Media and Communication)
Published: 29/06/2022

​“Be a critical thinker! Don't accept or easily assume. Look for the proof and learn how to build logical conclusions and arguments." – Dr Christo Rautenbach, MSc-graduate in applied mathematics (2009) from Stellenbosch University, and two doctoral degrees from the Telemark University College in Norway and the University of Waikato in New Zealand. He is also a former member of the Science Student Committee (NSC) at SU.

Dr Christo Rautenbach is a Coastal and Estuarine Physical Processes Scientist at the National Institute of Water and Atmospheric Research (NIWA) in New Zealand. He started his studies at Stellenbosch University with a BSc in Mathematical Science in 2005.  He also completed his BScHons in Applied Mathematics in 2007, and his MSc in Applied Mathematics in 2009 at Stellenbosch University. Christo then moved to Norway, where he did his first PhD at Telemark University College in Process, Energy and Environmental Engineering. Thereafter, he completed a second PhD in Earth Sciences (Physical Oceanography) at the University of Waikato, New Zealand.

His current position at NIWA primarily involves building ocean wave and currents prediction models. This work is based on his Applied Mathematics experience. He contributes to interdisciplinary coastal hydrodynamic, sediment-transport and water-quality research as part of a wider group of modellers within NIWA.  “I run these simulations on super computers and thus I also have to be fluent with programming languages," said Dr Rautenbach.

He also does a lot of work in the communication of science to policy: “I work with ecologists and anthropologists. Ultimately, my work could change laws – especially those related to climate change."

The thing Christo enjoys the most about the work he does is that it never gets boring and that no two days or projects are the same. He is also proud that his work makes a tangible difference in coastal communities. 

Dr Rautenbach said that his time at Stellenbosch University helped taught him to think critically. “Stellenbosch University mathematics and applied mathematics were super challenging but built the foundation for my career. Now, as a senior scientist, I stand out from the rest because of my solid foundation," he said.

Dr Rautenbach's advice to prospective students interested in his field is: “Be a critical thinker! Don't accept or easily assume. Look for the proof and learn how to build logical conclusions and arguments. Having said that, being pragmatic and results-focused will help you a lot, instead of getting lost in unnecessary details. The latter comes down to wisdom and learning from experience."

For more career profiles in the natural sciences, visit ​

This BSc-alumnus profile is part of the Faculty of Science's #100CareersinScience project. E-mail us at if you want to share your career journey with current students.

On the photo above, Dr Christo Rautenbach. Photo supplied