The industry of shipping and ship design involves a set of requirements and business strategies that aim at reliability, efficiency, keeping up with state-of-the-art technology and creating a competitive advantage. Inattention to ergonomics (or human factors) in the process may, however, jeopardize the safety of onboard operations and, in turn, implicate higher costs for the company. Ergonomics and user involvement applied to design through a User-centred Design (UCD) approach is believed to result in several success factors that improve the overall safety and quality of work and life onboard.This study explores and disseminates the success factors of UCD from which seafarers believe they can benefit as ship users. Such is done by cross-examining data from two focus group interviews comprised predominantly by participants with seagoing experience. The results show that the participants perceive UCD as an added value in terms of physical, cognitive, psychosocial and organizational improvements. Communication between stakeholders, usability, safety and satisfaction are a few of the categories that result from the identified success factors.This study conveys a comprehensive summary of the success factors collected in the focus groups, of the corresponding categories and of the affected dimensions of life and work onboard. Such findings represent the importance of UCD for those who operate ships and may serve as an incentive for ship-owners and designers to adopt a UCD approach, as well as for researchers to continue studying this subject further.