Measurements by drifting surface buoys. This system is a drifting mooring consisting of a surface buoy fastened to a floating anchor by a cable (trip line, buoy rope). It has to monitor as precisely as possible the water volume in which the floating anchor is immersed. The surface buoys are traced by Argos satellites.

The Global Sea Level Observing System (GLOSS) was established by the Intergovernmental Oceanographic Commission (IOC) of UNESCO in 1985 to establish a well-designed, high-quality in situ sea level observing network to support a broad research and operational user base. Various tide gauge networks have contributed to GLOSS, each with a different focus and each changing over time as research priorities evolve. The main component is the GLOSS Core Network (GCN), a global set of ~300 tide gauges that serves as the backbone of the global in situ sea level network. GCN gauges were allocated to each island or group of islands at intervals not closer than 500 km, and along continental coasts at intervals generally not less than 1000 km. Preference was given to islands in order to maximise exposure to the open ocean. Established in 1933, the Permanent Service for Mean Sea Level (PSMSL) is responsible for the collection, publication, analysis and interpretation of sea level data from the global network of tide gauges, including the GLOSS Core Network.

The Surface Ocean CO₂ Atlas (SOCAT) is a synthesis activity for quality-controlled, surface ocean fCO₂ (fugacity of carbon dioxide) observations by the international marine carbon research community (>100 contributors). SOCAT data is publicly available, discoverable and citable. SOCAT enables quantification of the ocean carbon sink and ocean acidification and evaluation of ocean biogeochemical models. SOCAT represents a milestone in biogeochemical and climate research and in informing policy. SOCAT data are released in versions. Each succeeding version contains new data sets as well as updates of older ones. The first version of SOCAT was released in 2011, the second and third version followed biennially. Automation allowed annual public releases since version 4. The latest SOCAT version (version 5) has 21.5 million observations from 1957 to 2017 for the global oceans and coastal seas. SOCAT contains data from the VOS, OceanSites network and mooring, buoy data in general as well as calibrated sensor data.

The Drifting Buoys GDAC -Global Data Assembly Centre- is the repository of surface drifters data. Both NRT -Near Real Time- and DM -Delayed Mode- data are available on the GDAC. Drifters report generally trajectories, sea-surface temperatures, atmospheric pressures at sea-level, as well as sea-surface salinity or sub-surface temperature in the ocean top layer.

The mission of OceanSITES is to collect, deliver and promote the use of high-quality data from long-term, high-frequency observations at fixed locations in the open ocean. OceanSITES typically aim to collect multidisciplinary data worldwide from the full-depth water column as well as the overlying atmosphere. OceanSITES delivers high-quality data from long-term, high-frequency observations at fixed locations in the open ocean.

Data from FerryBoxes on ships of opportunity going on permanent routes are stored inside this database (ferrydata.hzg.de). Parameters are temperature, salinity, chlorophyll-a fluorescence, oxygen and different others. The data model is transect oriented. A data portal to access and visualise the data is also provided.

SeaDataNet is a standardized infrastructure for managing the large and diverse marine data sets collected at sea by the oceanographic fleets, the ships of opportunity and the automatic observation systems. The SeaDataNet infrastructure network sand enhances the currently existing infrastructures, which are the national oceanographic data centres or data focal points of 34 countries, active in data collection. The networking of these professional data centres, in a unique virtual data management system provides integrated data sets of standardized quality on-line. As a research infrastructure, SeaDataNet contributes to build research excellence in Europe. SeaDataNet connects together more than 100 data centres aiming at preserving and making re-useable marine observations ranging from ocean physics to chemistry and biology. SeaDataNet infrastructure was implemented during the SeaDataNet project (2006-2011), grant agreement 026212, EU Sixth Framework Programme. The second phase, SeaDataNet 2 project (2011-2015), grant agreement 283607, EU Seventh Framework Programme has upgraded the SeaDataNet infrastructure into an operationally robust and state-of-the-art Pan-European infrastructure for providing up-to-date and high quality access to ocean and marine metadata, data and data products by: setting, adopting and promoting common data management standards, realizing technical and semantic interoperability with other relevant data management systems and initiatives on behalf of science, environmental management, policy making, and economy. SeaDataCloud project (2016-2020), grant agreement 730960, EU H2020 programme, aims at considerably advancing SeaDataNet Services and increasing their usage, adopting cloud and High Performance Computing technology for better performance.

EMODnet Physics provides a combined array of services and functionalities to obtain free-of-charge data, meta-data and data products on the physical conditions of European sea basins and oceans as recorded by more than 20.000 platforms (fixed stations, surface loads, ARGOs, HF radars, etc.) The system provides full interoperability with third-party software through WMS services, Web Services and Web catalogues in order to exchange data and products according to the most recent standards. EMODnet Physics builds on and is based on the cooperation and collaboration with the three established pillars of the European Oceanographic Community: 1) EuroGOOS and its Regional Operational Oceanographic Systems (ROOSs); 2) Copernicus Marine Environment Monitoring Service (CMEMS) , and in particular with the In Situ Thematic Assembly Center (INSTAC); 3) SeaDataNet network of National Oceanographic Data Centres (NODCs). Data are made available by EMODnet Physics, funded by the European Commission Directorate General for Maritime Affairs and Fisheries, in collaboration with Copernicus Marine Service (CMEMS) and EuroGOOS ROOSs INSTAC. Delayed mode data integrates the best available version of in situ data. These data are collected from national observing systems operated by EuroGOOS ROOS members, SeaDataNet NODCs completed by main global networks

The in-situ TAC integrates and quality control in a homogeneous manner in situ data from outside Copernicus Marine Environment Monitoring Service (CMEMS) data providers to fit the needs of internal and external users. It provides access to integrated datasets of core parameters for initialization, forcing, assimilation and validation of ocean numerical models which are used for forecasting, analysis and re-analysis of ocean physical and biogeochemical conditions. The in-situ TAC comprises a global in-situ centre and 6 regional in-situ centres (one for each EuroGOOS ROOSs). The focus of the CMEMS in-situ TAC is on parameters that are presently necessary for Copernicus Monitoring and Forecasting Centres namely temperature, salinity, sea level, current, waves, chlorophyll / fluorescence, oxygen and nutrients. The initial focus has been on observations from autonomous observatories at sea (e.g. floats, buoys, gliders, ferrybox, drifters, and ships of opportunity). The second objective was to integrate products over the past 25 to 50 years for re-analysis purposes... Gathering data from outsider organisations requires strong mutual agreements. Integrating data into ONE data base requires strong format standard definition and quality control procedures. The complexity of handling in situ observation depends not only on the wide range of sensors that have been used to acquire them but, in addition to that, the different operational behaviour of the platforms (i.e vessels allow on board human supervision, while the supervision of others should be put off until recovering or message/ping reception)°

GO-SHIP, the Global Ocean Ship-Based Hydrographic Investigations Program, is conducting repeat hydrography with high accuracy high precision reference measurements of a variety of EOVs through the whole water column. A selection of continent-to-continent full depth sections are repeated at roughly decadal intervals. The data archive for CTD data and bottle data is currently at CCHDO, although the CTD data from European cruises are available at Seadatanet as well.