Port State Control (PSC) guarantees that foreign ships do not jeopardize marine safety, security, and the environment when entering foreign ports. To share inspection information and improve the efficiency of PSC, countries in the same regions cooperate and follow memoranda of understanding (MoUs). Globally, a total of ten MoUs govern three different inspection regimes designed to select and inspect substandard ships. In this study, we use a super-slacks-based measure (super-SBM) to evaluate and compare the inspection efficiency of the three inspection regimes implemented by these ten MoUs and relies on the Malmquist production index (MPI) to identify the most applicable regimes. Our analyses produce three main conclusions. First, we use the average scores of the super-SBM in the past 11 years to confirm the efficiency rankings of the ten MoUs. Second, we combine the average efficiency scores of the three inspection regimes to show that the New Inspection Regime (NIR) is more economically efficient than other inspection regimes. Third, we use MPI scores to obtain a better understanding of the efficiency changes in MoUs’ productivity over time and confirm that the NIR is more stable than other inspection regimes.