The purpose of this paper is to report on the technical competency of volunteer surf lifeguards to perform CPR on a manikin in light of their lifeguard experience, age, and gender. The CPR skills of surf lifeguards on patrol at the beginning of the 2010-11 summer season were tested on manikins by observation of CPR procedures and electronic recording of compression and ventilation skills. Almost all lifeguards (n=252) made the appropriate initial checks for responsiveness (98%). Compression skills were generally performed accurately with few technical errors (such as incomplete release). Most lifeguards (87%) over-ventilated the lungs (> 600ml) on each breath and, of these, one third (31%) over-ventilated to a point that may worsen gastric distension (>1000ml). Males were significantly more likely (2 = 28.965, df = 14, p = 0.011) to over-inflate the lungs during testing. Reasons for poor performance are discussed and ways of addressing errors are suggested.