For lifeguards, recognizing a swimmer in trouble is a key factor in the rescue process. Although reports show that lifeguards outperform non-lifeguards in their surveillance task, it is unclear to what extent this difference is reflected in gaze behaviour. In the current study, gaze behaviour of nine novice and seven experienced beach lifeguards was recorded for 45 min while they were on active duty. Results showed that fixation duration of experienced lifeguards was longer and more variable than that of novice lifeguards, and that these differences were more pronounced when looking at the task-relevant region (i.e., swimming zone). Compared to experienced lifeguards, novices were found to be more distracted by the task-irrelevant regions when there were more people swimming. These findings suggest that experienced lifeguards use a more flexible and task-related gaze strategy, and that there might be differences in visual information processing between novice and experienced beach lifeguards.