The viewer allows interactive visualization of CTD data obtained monthly during RADIALES cruises (called RADCAN or RCAN cruises since 2013), specifically for four physicochemical variables: temperature, salinity, fluorescence, and dissolved oxygen. Unlike other RADIALES viewers, in this case only the data from the Cantabrian transects (Santander, Gijón, and Cudillero) are available. It displays a sidebar panel where you can select the desired option for a series of parameters (station, physicochemical variable, year, plot type, etc.) and a main panel where the graphs are displayed. It is organized into four tabs: [1] 'Plot' presents data from a single station (the list of all stations and their geographical coordinates can be found at https://seriestemporales-ieo.net and represented on a map in the fourth tab of this viewer). For each station, it allows selecting i) the simultaneous representation of profiles for the four physicochemical variables in a specific month , or ii) the time series of each variable at different depths. [2] 'Multipanel' shows the twelve monthly profiles of the selected station and variable, allowing the highlighting of profiles from particular years to facilitate interannual comparison. [3] 'Sampling dates' graphically represents the months for which data is available for each variable. [4] 'Stations Map' displays the map with the positions of all stations.