Light (solar short-wave radiation) transmission into and through sea ice is of high importance for various processes in Polar Regions. The amount of energy transferred through the ice determines formation and melt of sea ice and finally contributes to warming of the uppermost ocean. At the same time the amount and distribution of light,as the primary source of energy, is of critical importance for sea-ice associated organisms and bio-geochemical processes. However, our current understanding of these processes and their interdisciplinary interactions is still sparse. The main reason is that the under-ice environment is difficult to access and measurements require large logistical and instrumental efforts. Particularly, it was not possible to map light conditions under sea ice over larger areas. Here we present a detailed methodical description of operating spectral radiometers on a remotely operated vehicle (ROV) in the Central Arctic under sea ice. This new measurement concept resulted in a most comprehensive data set of spectral radiance and irradiance under and above sea ice, complemented through various additional in-situ measurements of sea-ice, snow, and surface properties. Finally, such data sets allow quantifying the spatial variability of light under sea ice, especially highlighting differences between ponded and white ice as well as different ice types.