A comparison among three Compact-Polarimetry (CP) Synthetic Aperture Radar (SAR) architectures is followed to analyze some polarimetric features sensitivity with respect to the ocean background variation, which is achieved as situational awareness about the environment influence on detection algorithms performance. Thus, architectures are emulated from Radarsat-2 full-polarimetric actual SAR data, according to wave polarimetry concepts. In this analysis, the entropy of the wave scattered off the observed scene is used as polarimetric feature, considering as reference the conventional target entropy evaluated from full-polarimetric SAR data. Then, actual RISAT-1 Hybrid-Polarity (HP) data are analyzed extracting other polarimetric features to investigate their capabilities to discriminate metallic targets from the ocean background. Relative ocean background sensitivity analysis is addressed using an objective metric named Relative Sensitivity of Polarimetric Features (RSPolF), whose characterizes the polarimetric feature sensitivity for the sea state found in each SAR scene. Additionally, on further works, it can objectively support target detection algorithms for threshold definition.