This dataset contains temperature, salinity, fluorescence and dissolved oxygen measurements collected from 2015 to 2019 in the Northern Antarctic Peninsula and vicinities, between 60 and 65 degrees of south latitude. During this period, a total of five cruises were carried out in the area by the High Latitude Oceanography Group (GOAL-FURG), all during the austral summer of the respective years. The NAUTILUS project aims to obtain data in the Antarctic Peninsula to contribute to the knowledge of the freshening of waters around Antarctica and the understanding of the role of dense waters in the acidification of the Southern Ocean. Salinity and temperature were measured using CTD (conductivity, temperature, and depth), and fluorescence and dissolved oxygen were obtained using auxiliary sensors installed in the CTD.