Professional ship management, i. e. the management of ships by third parties on behalf of their owners, has grown in importance in international shipping. This research investigates the relationship between professional ship managers and their clients in order to lay down the foundations for optimal marketing strategies directed towards retention of current clients and prospects over the long-term. Professional ship management has been described as an efficient organisational. adjustment to the needs of the global shipping market and a way by which western countries have been trying to sustain their global maritime dominance (Sletmo 1989). Despite this, ship management has received little attention from academia. The importance of the subject area and the limited scientific attention it has received, make professional ship management worthy of scholarly consideration. A review of ship management was undertaken in order to ascertain current marketing policies and problems faced by the industry. Frequent client defections and client uncertainty and dissatisfaction coupled with marketing directed towards client attraction (mainly promotion) resulted in identifying that application of relationship marketing may be beneficial for professional ship management. A review of the relationship marketing literature supported the application of the concept in a ship management context and assisted in developing a conceptual model. The conceptual model aimed towards identifying the dimensionality of ship manager-client relationships and their classification. Classification involved carrying out tests to identify whether ship management companies may be assembled into segments on the basis of their client relationships, and if so, whether particular characteristics of the interacting organisations may be found in particular relationship segments. Analysis of the data obtained from telephone interviews with a sample of ship managers in the United Kingdom and Cyprus resulted in the identification of the dimensions in ship manager-client relationships. A subsequent questionnaire to the respondents aimed at identifying the organisational characteristics of the companies and obtained structured responses to the relationship dimensions. Application of cluster analysis indicated the existence of four segments of ship management companies on the basis of their client relationships. The clusters obtained were validated and also supported on a theoretical basis from the relationship marketing literature. Preliminary investigation between organisational, characteristics and cluster membership indicated that companies in particular relationship segments share certain similar organisational characteristics. Multiple discriminant analysis assisted in identifying those organisational characteristics that are more strongly associated with cluster membership. A discussion of the results provides serious implications for practitioners, be it professional ship management companies or their clients. The research shows that ship management companies may be facing problems due to their client relationship attitudes, that the ship management industry is segmented in terms of service providers and that clients can have a choice of ship manager based on their individual needs. Companies with particular client relationships may face problems like short-term contracts and client defections. Based on the study, ship management companies will be able to address and combat such problems. Furthermore, implications for theory development, research methodology in a maritime context and scope for further research in professional ship management are discussed.