Research on simulator training has rarely focused on the way simulated contexts are constructed collaboratively. This study sheds light on how structuring role-play and fostering social interactions may prove fruitful for designing simulator training. The article reports on a qualitative study of nautical students training in a ship simulator. The study examines how a group of students, together with a professional maritime pilot, enacted professional roles and collaboratively constructed a simulated context for learning to navigate. Their activities on the bridge were framed within the maritime profession's hierarchical system of captain and officers, and we examine in detail how these institutionally defined positions become important resources for meaning-making during role-play. The article portrays how two competing activity contexts were constructed, and how the role-play provided opportunities for enacting professional roles and work tasks. However, it also shows that it is challenging to pick up on what is significant to learn and to confront this in debriefing. The article concludes that the students' collaboration and meaning-making is an entity of training that may be more efficiently addressed.