A single marine overlay display is more efficient than separate chart and radar displays

Performance with marine chart and radar images displayed on adjacent screens was compared to performance with chart and radar images overlaid on a single screen. Eighteen college students and nine mariners read statements about the radar image, the chart image, or both images and answered ‘True’ or ‘False’ to each statement after viewing the displays. Accuracy was equal for separate and overlay displays, but viewing time was shorter and efficiency (accuracy/viewing time) was higher for overlay displays. Observers then re-aligned radar displays that had been translated and rotated out of alignment with the charts. They took longer but were more accurate on the overlays. Students and mariners performed similarly on both tasks.