The present study compares professional seafarers and private leisure boat users in Norway and Greece. The aims of the present study are to examine the safety behaviours related to personal injuries and accidents among these groups and to study the factors influencing these behaviours. This will serve as a backdrop to a general discussion of why the level of fatalities is higher among private boat users than among professional seafarers and what the former may learn from the latter. The study is based on surveys to crew members on Norwegian and Greek cargo and passenger vessels and leisure boat users in Norway and Greece. Our study indicates that while unsafe behaviours related to work pressure and risk taking are important among professional seafarers (i.e. risk acceptance and violations), unsafe behaviours related to the leisure/holiday situation was important for the leisure boat users (i.e. alcohol use while driving a boat). Additionally, we discuss how the situation of private leisure boat users is less regulated than that of professional seafarers. Our study indicates that both in the professional and the private setting, norms for interaction and conduct seem to be influenced by norms and expectations rooted in different socio-cultural groups, e.g. the national culture, the specific sector in question, the organisations and in peer groups.