The decision support system studied in this project was developed by Wärtsilä and is called Advanced Intelligent Manoeuvring (AIM), aligning with “low-level automation” or Level 1 (out of a 4-level progression) of MASS. AIM can generate suggestions for course or speed alterations based on data from surrounding traffic. A full-mission bridge simulator study was conducted at Chalmers University of Technology in Gothenburg, Sweden with nineteen Swedish navigators. Three traffic scenarios each with three ships were completed in both baseline (no AIM) and AIM conditions. A mixed methods data collection and analysis approach was employed using questionnaires, collective interviews, and an evaluation of the ship tracks.