The human element is increasingly acknowledged as an important factor contributing to accidents at sea. What is infrequently considered however, is the extent to which social isolation, and its effects on seafarers, contributes to both marine incidents and to the problems of seafarer retention currently experienced throughout the industry as a whole. This paper draws on the findings of several related studies undertaken at the Seafarers International Research Centre (1999-2002) along with a number of published studies on seafarer health. In doing so it considers both the causes and potential effects of social isolation on seafarers. These areas have not traditionally been subject to systematic scrutiny and analysis. As such they are substantially under-researched and are often under-emphasised by policy makers and practitioners in the maritime sector. Using participant observation and detailed qualitative studies the paper explores these issues in an effort to bring them on to the accident prevention agenda and to highlight the need for further detailed research in this area. In drawing to a conclusion the paper highlights a number of steps that could be taken by shipping companies to militate against social isolation and to encourage better mental health amongst modern day seafarers.