To eliminate the influence of target returns on the estimation of local sea clutter distributions, an improved iterative censoring scheme (ICS) for constant false-alarm rate detectors is proposed with two modifications. First, the proposed ICS censors out both target pixels and their four-connected neighborhood pixels from the estimation of local sea clutter distributions. Second, a novel initial detector is proposed to improve the convergence speed of ICS. The proposed initial detector, which only needs the probability of false alarms as an input parameter, is based on the sorting of all pixels under test. Experiments of ship detection with RADARSAT-2 ScanSAR wide mode images are presented to illustrate the effectiveness and improvements of the proposed ICS.