The U.S. maritime industry operates more than 10,500 vessels that transport essential energy, food, and goods across inland and ocean routes. Yet the sector faces a shrinking skilled workforce, declining academy enrollment, and a series of high-profile misconduct incidents that have exposed systemic issues of culture, supervision, and accountability.Guided by the statement of task, the National Academies of Sciences, Engineering, and Medicine convened an ad hoc expert committee to assess and inform public policies governing alcohol possession and consumption by crew and other personnel aboard U.S. commercial vessels. The assessment considered personal safety, security, and welfare aboard vessels; the interplay of alcohol with other intoxicants; and the operational and workplace factors influencing misuse. The committee examined how alcohol and other substances contribute to abusive and dangerous behaviors; evaluated the effectiveness of federal regulations and vessel operator policies; and reviewed best practices for prevention, education, training, reporting, and accountability to foster a culture of safety.Strengthening Alcohol Policies and Supporting Safety and Health in the Maritime Industry presents a comprehensive, evidence-informed strategy to address these interconnected issues. The report examines how alcohol and other substance use, workplace culture, leadership, and policy environments interact to shape safety and well-being at sea. The report offers actionable recommendations to modernize alcohol and drug policies, strengthen prevention and response to sexual misconduct, improve data collection, support mariner health and well-being, and reinforce leadership accountability. Together, these insights provide a roadmap for fostering safer, healthier, and more supportive conditions across the maritime workforce, helping position the industry for long-term strength and sustainability.