Аннотация:The paper presents an overview of the current marine observational systems which provideprimary information for operational monitoring and predicting the variability of the main hydrophysicalfields on the scales from several tens to several thousand kilometers (of the order of the Rossbybaroclinic deformation radius and higher). Such systems provide the regular implementation of oceanographicand marine meteorological observations, their rapid interpretation and delivery to users; this is asubject of a relatively new discipline, operational oceanology. The active development of this disciplineduring the recent two decades suggests that the forecasting of the marine environment state willeventually reach the same level of accuracy and reliability as in operational meteorology, a more successfuland older discipline.