The Algoa Bay Sentinel Site (ABSS) located within the warm-temperate Agulhas Bioregion is the most comprehensive coastal observation network in South Africa spanning some 300 km of coastline between Port Alfred and Oyster Bay. Established in 2008, the ABSS now comprise more than 40 in situ coastal sensor moorings, 29 acoustic receivers, nine estuarine sensor moorings (temperature and salinity) and eight Pelagic Ecosystem Long-term Ecological Research (PELTER) sampling stations. Submerged coastal sensors measure water temperature, the velocity and direction of currents, swell waves and gives valuable insight into how the physical environment is influenced by meteorological factors like winds and rainfall. The PELTER programme was established in 2010 and involves monthly sampling (~90 surveys to date) of key essential ocean (EOV) and biodiversity variables (EBV) focussed on biogeochemical and plankton dynamics in Algoa Bay. Additionally, biological communities from the sandy beaches, rocky shores, subtidal reefs and islands are sampled at monthly to annual intervals. The objectives are to identify spatiotemporal trends of these key variables including the factors shaping their dynamics. These data types are also useful when studying ecosystem responses to periodic extreme meteorological, oceanic or biological events. Deep learning of such details not only aids the management of coastal ecosystems but also strengthens our ability to estimate how these aspects may change going forward. Algoa Bay is also a dynamic socio-ecological system where a productive coastal ecosystem interfaces with a vibrant socio-economic environment. As a natural socio-ecological laboratory, ABSS is thus well poised to make a meaningful contribution to regionally unique research opportunities in support of the grand challenge, which is to sustainability unlock South Africa’s blue economy.