Surface wave (SW) over the horizon (OTH) radars have been widely used for remote sensing and oceanic applications. These systems operate continuously for monitoring both sea currents and waves by analyzing the signal backscattered by the rough sea surface. This paper is devoted to the statistical analysis of sea backscattering recorded by the oceanographic Wellen radar (WERA) system, developed at the University of Hamburg. Data were collected on May the 13th 2008 at two different sites in the Bay of Brest, in Brittany, France. The results show that for near range cells the signal amplitude fits well the Rayleigh distribution, while for far cells the data show a more pronounced heavy-tailed behavior. The causes can be traced in man-made (i.e. radio communications) and/or natural (i.e. reflections of the transmitted signal through the ionosphere layers) interferences. A qualitative analysis of the spectral characteristics of the received signal concludes the work.