The objective of this work was to assess whether the implementation of a bridge resource management (BRM) unit into the simulator-based nautical training of the German Navy is effective in improving non-technical skills and navigation performance. To this end, questionnaire data, observations of behaviour and performance outcomes were compared between a control group and an experimental group. Data of 24 bridge teams (126 sailors) were used for the analyses. Ten teams received BRM training and 14 teams served as the control group with unchanged simulator training. Reactions to simulator training were positive in both groups but more favourable in the control group. In the BRM group, significantly more positive attitudes towards open communication and coordination, more frequent sharing of information and fewer collisions were found than in the control group. Effect sizes were rather small. This may be due to the limited scale of the BRM unit, which consisted of only one instruction-training-feedback cycle. The extension of BRM-related feedback to all simulator runs of the nautical training can be expected to produce larger effects on attitudes, behaviour and performance.