Lack of appropriate supervision is a persistent risk factor in most child drowning incidents. The risks to young children associated with swimming at beaches place a premium on close and constant supervision by caregivers. However, little is known about caregiver supervisory practice and perceptions of child water safety at beaches. Adults (N = 769) in charge of children under 10 years of age were surveyed at 18 New Zealand beaches during the summer of 2007 to ascertain caregiver perceptions of their water safety skills, risk of drowning for their child and their supervisory behaviours. Most parents (78%) estimated that they could swim 100 m non-stop in open water, almost one half (48%) had been certified in cardio-pulmonary resuscitation and one quarter (24%) had received some rescue/lifesaving training. More than one quarter (29%) failed to provide appropriate supervision for their under 5-year olds at the beach. Almost half (46%) of caregivers did not provide close supervision for their 5-9 year olds. Although there were no significant differences between males and female self-reported supervision, male caregivers were more likely to rate their 5-9 year olds as good swimmers and less likely to estimate a high risk of drowning for that age group. To address shortcomings in caregiver supervision, it is suggested that water safety education initiatives emphasise how to provide close and constant supervision of young children at beaches. Furthermore, a focus on the necessity for caution when estimating risk and ability to cope with open water conditions is recommended.