The Sentinel Sites for Long-Term Ecological Research (SSLTER) programme includes three Sentinel Sites: Algoa Bay SS in the Eastern Cape (established in 2008), Natal-Bight SS in KwaZulu-Natal (rolling out in 2018), and the Two-Oceans SS in the Western Cape (rolling out in 2018). In addition, Satellite Sentinel Sites (SSS) will be established along the West Coast, Mossel Bay, Wild Coast, Sodwana Bay, and the Prince Edward Islands (sub-Antarctic). Each Sentinel Site will consist of continuous in situ observatories (thermistor strings, shallow underwater temperature recorders, current and wave sensors) at selected sites as well as a pelagic ecosystem programme to collect physical, chemical and lower trophic biological data on a monthly basis from selected stations in the Sentinel Site. Satellite Sentinel Sites will consist of a single coastal observation mooring collecting a suite of variables (including pCO2, pH, telemetry, currents, waves, temperature, etc.) near real-time. Sentinel Sites will be restricted to South Africa. The aim of the Sentinel Sites is: 1) to carry out an intensive study of a small section of the coast and then apply the results to the larger ecoregion; 2) to tap into South Africa’s geographical advantage by providing access to cutting-edge research platforms and data in all the coastal biogeographic regions from the three oceans and so to stimulate innovative research and IP generation that is of global relevance; 3) to create dynamic natural laboratories for carrying out multi-disciplinary, multi-institutional field-based research, and 4) provide comparable datasets from sites around the entire coastline.