The paper presents the results of complex observations of the characteristics of mesoscale eddy structures carried out in May-June 2019 in the Norwegian Sea. Satellite altimetry data from the AVISO archive, radar images from the Sentinel-1 satellite, and hydrological observations of currents, temperature, and salinity taken from the research vessel Academiс Nikolai Strakhov were analyzed. From the data on the dynamic surface of the ocean level, it was found that in the Lofoten Basin of the Norwegian Sea, groups of eddy structures of various types of rotation were constantly present in the described period. This was confirmed by ship observation data. In the same period, predominantly small eddies with an average diameter of about 15 km appeared in radar images. Among the long-lived (more than a month) structures recorded by satellite altimetry, anticyclones 40-60 km in size predominated, and eddies were noted both constantly existing in the region and coming into it. To study the structural features of the eddies arriving in the region, for example, from the periphery of the Norwegian current, an experiment involving satellite survey was performed. An anticyclone with a diameter of about 45 km was recorded based on hydrological and altimetry measurements. The eddy did not appear on the surface in the temperature field, but was clearly visible at depths of more than 50 m in the form of a plume of warm and more salty water, its vertical development was 200-400 m. The anticyclone manifested itself in the current velocity field from a depth of 25 m, and velocities at its periphery reached 30-50 cm/s, which was higher than the estimates obtained from satellite data.