Vessel Traffic Service (VTS) is a service to the maritime community implemented topromoteand improve maritime safety. In recent years VTS has become a topic of increased interest formaritime stakeholders and the general public. To derive insights on how maritime safety is constructedin the VTS domain this exploratory study was conducted. Four VTS centres were visited and 15 VTSoperators were interviewed and observed at work. Further a focus group interview with 8 VTS operatorswith focus on decision support tools in the VTS domain was conducted. The results of the study indicatethat VTS operators define maritime safety as context-dependent a condition which is formed by theirindividual actions. Regulations and guidelines exist, but do not shape the daily work of the operators asmuch as their own experience and expertise. Safety arises in the interaction between the individual actorand others; it is influenced by contextual aspects, such as traffic density or weather conditions, rather thanby what is stated by the regulating organisation.