The WAVY family of drifters, developed in the EU H2020 project MELOA, range from small drifters suitable for beach and surf zone studies to somewhat larger drifters, tailored for coastal and long-term open ocean observations, and consists of fve members, namely the WAVYs Basic (WB), Littoral (WL), Ocean (WO), Ocean-plus (WP) and Ocean-Atmo (WA). The WB and WL are currently at TRL 8, having been validated and used in real operational environments in a series of demonstrative use cases; the WOs are currently at TRL6 and undergoing use cases designed to bring them to TRL8. This paper presents the latest work done in the validation of three capabilities of the drifters: tracking of the ocean’s surface currents; measurement of wave parameters and measurement of sea surface temperatures.