The CALYPSO system is an operational network of High Frequency (HF) radars, based on CODAR SeaSonde technology, that provides real-time maps of sea surface currents across the dynamically active Malta–Sicily Channel. The initial CALYPSO project established three radar stations at Ta’ Barkat (Malta), Ta’ Sopu (Gozo), and Pozzallo Harbour (Sicily). These combine their radial measurements to generate hourly current vectors on a regular grid using a 13.5 MHz operating frequency. Follow-up initiatives, notably CALYPSO South, expanded the network to seven sites, extending the monitoring footprint to cover the entire Maltese marine area and south-eastern Sicily, with a total expected coverage of around 15,000 square kilometres. Beyond environmental protection, the high-resolution data support search and rescue (SAR) operations, help identify the origin of marine spills, contribute to safer navigation, and improve meteo-marine forecasts for the responsible authorities in Malta and Sicily.