This chapter examines the role that Elder Dempster played in transporting so-called ‘lunatics’ between the United Kingdom and British West African colonies in the first half of the twentieth century. Many Europeans inhabiting the colonies and many more colonial subjects traveling abroad in the UK and other West African territories succumbed to mental illnesses while far from home. When this occurred and the patient was deemed likely to benefit from repatriation, Elder Dempster was typically the agent charged with providing transport. As such, Elder Dempster frequently had to negotiate with the Colonial Office about the practicalities of transporting lunatics. The cost of transport and who was to pay, the types of accommodations necessary for mentally ill passengers, and considerations of liability all had to be orchestrated to the satisfaction of the commercial shipping giant. This chapter argues that the relationship between Elder Dempster and the British government represents an example of the importance of public-private cooperation in the maintenance of the medical geography of Empire, even as it reveals significant tensions underlying such cooperation. In so doing, it helps to move the historical study of psychiatry in colonial Africa into a broader engagement with its international, transnational and commercial influences.