The current international framework that purports to regulate the spread of communicable disease in the context of maritime traffic is a fragmented, internally inconsistent, and inadequately enforced patchwork of treaties (including the International Health Regulations (2005)) and customary international law. The COVID-19 pandemic has tested the current framework and revealed it to be inadequate to deal with a major global health emergency. States have imposed or failed to impose varying control measures, the effects of which have been witnessed on board passenger vessels around the world. The cruise industry, in particular, has a significant global economic impact; therefore, appropriate, enforceable international regulation is necessary to ensure the adequate control of future communicable disease outbreaks.