Technology: National Sea Rescue Institute launches cutting edge rip current experiment
The National Sea Rescue Institute (NSRI) Drowning Prevention team, together with the City of Cape Town’s Recreation and Parks Department, is working on a research project, studying rip currents and developing educational content based on aerial footage filmed in False Bay and Table Bay. In a first for Cape Town, a research permit has been issued by the national Department of Forestry, Fisheries and the Environment for the deployment of a dye that will highlight and visually expose the flow of rip currents in the ocean. The experiment will use a non-toxic fluorescein dye to expose the flow of rip currents and help with beach safety education and awareness efforts. The dye is non-toxic to the environment as well as people. The footage captured will be used as part of a focused rip current/beach safety public awareness campaign as preparations for the summer season are under way.
NSRI Drowning Prevention Manager, Andrew Ingram, said they have been granted the permit to deploy the fluorescein dye, according to global best practice among ocean researchers. Fluorescein is commonly used by scientists and plumbers in different water tracer experiments, as well as by carp fishermen and is harmless.
The first dye release took place last month at Kogel Bay and after studying the results from this experiment, the second release which will be filmed, will take place at Strand beach.
Using the South African Weather Service’s experimental rip current forecast model, along with their standard operational coastal forecast systems, the rip current research team identified a strong likelihood for rip currents to occur on Wednesday, 20 October 2021.
Rip currents are powerful channels of fast-moving water. A rip is an area that is often without wave activity and appears darker and deceptively calmer than the rest of the ocean. These currents move fast and can be deadly, as panicked swimmers often try to counter them by swimming straight back to shore, putting themselves at risk of drowning because of fatigue.
“One of the top reasons for drownings at our beaches is swimming where there are no lifeguards present. The absence of lifeguards is the first indicator that it isn’t safe to swim there. Aside from emergency rescues, City of Cape Town lifeguards work closely with the NSRI to examine the surf and determine the safest swimming beaches. Only beaches where the red and yellow flags are put up and where lifeguards are on duty, are deemed safe. Outside of those areas, the coastline can be deceptively attractive for bathers looking for a quiet spot or secluded area to swim. In many instances, the surf is unsafe and bathers can quickly lose their lives in the unfortunate event that they get caught in a rip current,” said the City’s Mayoral Committee Member for Community Services and Health, Councillor Zahid Badroodien.
“The City is always looking to use technology and experience to find new ways to educate the public on water safety, especially as beaches get busy during the festive season. We appreciate the positive working relationship with the NSRI and look forward to taking advantage of the powerful medium of social media to share the video footage with the public, raising awareness of the dangers of the ocean to encourage swimming in areas clearly marked safe and where lifeguards are on duty,” added Councillor Badroodien.
Sources: NSRI, City of Cape Town media office