Purpose: The aim of this study was to analyze the different phases of a water rescue, their influence in the whole lifesaving and if lifeguards could be differentiated according to their abilities during a water rescue. Methods: A cross-sectional study was carried out to analyze the different phases and lifeguards abilities of a simulated water rescue of 100 m. Thirty-four professional lifeguards performed the test and the time was recorded for the first phase (swimming to the victim), the second phase (towing back the victim) and the third phase (extracting the victim). A discriminant analysis was conducted in order to classify lifeguards in two groups (high or medium level of abilities during the water rescue) and the times were compared on each phase. Results: The time during the second and the third phase classify correctly the lifeguards according to their level of abilities. Lifeguards with higher level of abilities performed the water rescue significantly faster, specifically during the second (p < 0.001, ES =1.38, large) and the third phase (p =0.002, ES = 1.09, medium), but no differences were found in the first part of the water rescue (p > 0.05). Conclusion: The time of a simulated water rescue seems to be a good method to classify lifeguards according to their abilities. These findings could allow rescue teams to know the skills of their lifeguards and design strategies in order to decrease risks and enhance lifesaving.