Safety management regulation is an important supplement to market forces to establish a sufficient safety level in high-risk industries. The accident statistics in Norwegian maritime passenger transportation display a paradox: personal injuries have decreased while ship accidents have increased in the period during which safety management has been regulated (the International Safety Management Code was effectuated in the late 1990s). We interview regulators, shipping company management, and crewmembers about their practices and opinions regarding safety management regulation and use these data to explore how this regulation influences safety management practices to prevent different types of accidents. This study underlines earlier research showing that regulation serves to ‘raise the bar’ by heightening the industry levels of safety investments and organizational safety awareness. In addition, our results suggest that safety management regulation in maritime transportation is mostly effective for preventing personal injuries in cases in which the personal have sufficient time and resources available, and the procedures are consistent with seafarers’ professional values. For ship accidents, such as groundings, other causal factors come into play. We find that the negative consequences of regulation (proceduralization) in particular influence the performance of safety-critical tasks, such as navigation. This may explain why personal injuries have decreased while ship accident frequencies have continued to increase in spite of the regulations aimed at improving safety.