Data have been collected during the POSEIDON network operation and are easily accessible through a web interface to the system's database. The database is updating on a daily basis offering full access both to archived and recent data. The user has also access to multiple metadata information regarding the buoys sensors, location, operational period and other combined information.

The POSEIDON operational center receives, processes and analyzes all the data on an operational basis. These data, which are archived and utilized for forecast and research purposes need management, which means efficient storage, cleaning (pre data mining process), and availability in-source for the production of forecasts and other scientific issues and outsource (other institutes, web generally). The operational center receives the above data on a 3-hourly basis. They are stored in text files and then are transferred to a normalized mysql database. 

The data base has been designed to support fast access to all available parameter values and their metadata. Appropriate links have been established to associate the transmitted data with their metadata and the relevant quality control flags which assigned to the data providing a reliability score of the recorded values. This quality control process is an integral and important part of the operational process. Its significance derives from the fact that ocean data measurements are sparse and often present a variety of dubious and false values. Bio-fouling, sensor failures, anchoring and transmission problems are among the common causes of corrupted data. In terms of operational activities, this analysis must be held in real-time conditions and has to be as reliable as possible.

Data are freely available in the POSEIDON database: http://poseidon.hcmr.gr/listview.php?id=136.