Life aboard a merchant ship exhibits peculiar sociological connotations. The ship is the seafarer's workplace, but it is also the place to rest, enjoy free time and relate to other individuals. The human group that is known as crew is, nevertheless, structured as a hierarchical and departmental system, in which the professional role accompanies each individual around the clock. This will give place to a series of small sub-groups, which will in turn divide further if their components come from different countries. All this happens within an environment that is in constant motion, isolated from society, afar from family and home. The seafarer develops thus a conduct and behaviour that makes him feel different from others, which may later on hinder his fitting back into the onshore society. Studying this sociological reality becomes essential for those who are in charge of designing the crew, and for those, such as Captains and officers, who have to organise their life and work on board. The present work analyses the sociological reality of the crew aboard a merchant ship from a total institution perspective. It examines the set of relationships that are established amongst the crew, as well as their connection to the outer world. It further proposes possible crew selection and organisation criteria. The Merchant Ship. A Sociological Analysis deals with a highly significant subject in the development of nautical activities, and is addressed to seafarers, students, shipping companies and other individuals and entities related to the merchant marine. It may also be of interest to those studying Social Sciences.