Introduction The purpose of this study was to analyse how the rescue equipment and the automatic compression mechanism influenced the cardiopulmonary resuscitation (CPR) after a water rescue on the beach. Methods The sample of our research composed of a group of 65 lifeguards (51 men and 14 women). The lifeguards carried out a 5 minute CPR pretest. Afterwards, the sample was randomly divided into two groups. Both groups performed a test: a water rescue, and immediately afterwards 5 minutes of CPR. One group did not have any additional rescue material, while the other used flippers and a rescue tube to swim. The group with the rescue material performed a CPR with an automatic compression mechanism, the Lund University Cardiac Arrest System. Results The use of the automatic compression device improves the conditions in the correct compressions in CPR after a water rescue: (manual: 283±145.25; automatic: 352±119.74, p=0.042). There was no significant difference in the correct breathing (p=0.758). During the water rescue the lifeguards equipped with flippers and a rescue tube were faster (227±69.28 s) than the lifeguards who had not used any additional equipment (271±43.06 s, p=0.003). Conclusion The use of flippers and rescue tube improved the rescue time. The CPR quality when the lifeguard was exerted worsened significantly, but the use of the automatic mechanisms of compression improved the performance of quality chest compressions. This was not the case with the ventilations, these being of poor quality in both groups. (Hong Kong j.emerg.med. 2014;21:291-299)