Seeing Is Not Knowing: Situational Awareness in Three Levels

Not Just Seeing

Situational awareness is one of the five principles named in bridge resource management, and it is the one most often cited in casualty reports as lost. A widely used model, by the psychologist Mica Endsley, divides it into three levels:

1. Perception. Noticing the elements: the target on the radar, the depth, the set, the alarm.
2. Comprehension. Understanding what they mean together. A target on a steady bearing is a collision risk, not just a target.
3. Projection. Predicting what will happen next and when. Where will we be in ten minutes, and what changes if the current is stronger?

People lose awareness at any level. Missing the target is a Level 1 failure. Seeing it and thinking it will pass clear is Level 2. Understanding it and failing to see the consequence in time is Level 3.

Cases

• IMCA SF 03/24. The OOW lost situational awareness near a wind turbine safety zone and turned to port when starboard was right given the north-to-south tide. He was new to the vessel and its slow-speed handling with a tow (a Level 3 problem: he could not project how she would respond). He also did not tell the Captain when control was lost.
• Meshka, 2025. The first transit of the Öresund for that vessel and crew. The traffic centre noticed her drifting outside the lane before she grounded in three metres of water.
• IMCA SF 17/26. The report cites poor shared situational awareness between two bridges. Each had a picture, and they did not have the same one.
• AIS-assisted collisions. A bridge team trusting one data source more than it deserved.