Volunteers Marc de Vos and Marilyn Wells developed computer models that help the National Sea Rescue Institute save lives.
Western Cape, South Africa (09 April 2025) — The beating heart of the National Sea Rescue Institute (NSRI) is its volunteers. These people offer their time, effort, skills and bravery to bring people facing struggles at sea home. Some volunteers go above and beyond for the NSRI, like volunteers Marc de Vos and Marilyn Wells. De Vos and Wells have not only served in leadership positions, but they have also developed computer models that help the team on the shore save lives.
Narrowing Down the Search
Marc de Vos is a former Station Commander and Class 1 Coxswain at Table Bay’s Station 3. But he’s also a marine weather scientist. With these two worlds of experience, Marc used knowledge from his profession alongside an informed opinion of what rescue operations need to create a helpful computer model designed to speed up search times.
Marc’s model, ‘SARMarc’ helps calculate the drift paths of missing people and vessels (the direction in which a person/vessel is heading taking into account currents and wind).
Thanks to the program’s search pattern abilities, the NSRI is able to cut down on search time and allocate resources to rescues far better, ultimately making the process of saving lives that much smoother.
Like Marc, Marilyn also contributed to how the NSRI tracks people and vessels at sea in a big way. Thanks to her background in software development and teaching as well as her role as Deputy Station Commander (Station 26, Kommetjie), Marilyn knew that calculating drift predictions needed to be done more accurately, faster and with flexibility.
Marilyn developed a model dubbed ‘SearchWell’ to predict where a casualty might end up based on its understood starting point. The model can then transfer these prediction coordinates to GPS systems on boats and in aircraft, with the ability to quickly recalculate should new information come into play.
While SARMarc used weather patterns and oceanography-driven information to estimate drift paths, SearchWell streamlines these estimations through formulas that allow for real-time navigation!
SARMarc and SearchWell can work together, as was the case recently when the case of a missing Spanish diver saw the NSRI use both computer models.
“The integration of SARMarc and SearchWell models has revolutionised the efficiency and accuracy of NSRI rescue operations,” Charl Maritz, NSRI’s Operations Manager, praised.
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