Meike Martins¹, Taco De Bruin², Birgit A Klein¹, Simo-Matti Siiriä³, Kevin Wiegand Sr⁴, Waldemar Walczowski⁵, Henry C Bittig⁶, Malgorzata Merchel⁷, Tsuysohi Wakamatsu⁸, Violeta Slabakova⁹, Lara Díaz-Barroso¹⁰ and Melanie Juza¹¹, (1)BSH Federal Maritime and Hydrographic Agency, Hamburg, Germany, (2)NIOZ Royal Netherlands Institute for Sea Research, National Marine Facilities (NMF), Den Burg, Netherlands, (3)Finnish Meteorological Institute (FMI), Helsinki, Finland, (4)Federal Agency of Hydrography and Maritime Affairs (BSH), Physical Oceanography, Hamburg, Germany, (5)Institute of Oceanology of the Polish Academy of Sciences, Sopot, Poland, (6)Leibniz Institute for Baltic Sea Research, 18119 Warnemunde, Germany, (7)IOPAN, Sopot, Poland, (8)Nansen Environmental and Remote Sensing Center, Bergen, Norway, (9)Institute of Oceanology - Bulgarian Academy of Sciences, Department of Ocean Technologies, Varna, Bulgaria, (10)SOCIB, Palma, Spain, (11)Balearic Islands Coastal Observing and Forecasting System (SOCIB), Palma, Spain