Aquatic competencies have been proposed as a prevention strategy for children aged 2–4 years who are over-represented in drowning statistics. For this recommendation to be made, exploration of the connection between aquatic competencies and drowning is required. This review critically analyzed studies exploring aquatic competencies and their effect on drowning and/or injury severity in children 2–4 years. English language peer-reviewed literature up to 31 July 2019 was searched and the PRISMA process utilized. Data were extracted from twelve studies that fulfilled the inclusion criteria. Findings from this study included that aquatic competencies were not found to increase risk of drowning and demonstrated children aged 2–4 years are capable of developing age-appropriate aquatic competencies. Age-appropriate aquatic competencies extracted were propulsion/locomotion, flotation/buoyancy, water familiarization, submersion and water exits. The acquisition of these competencies holds benefit for the prevention of drowning. No evidence was found relating to injury severity. There was limited exploration of the relationship between aquatic competencies attainment and age-related developmental readiness. The review highlights the need for consistent measures of exposure, clarity around skills acquisition, better age-specific data (2 years vs. 3 years vs. 4 years), studies with larger sample sizes, further exploration of the dose–response relationship and consistent skill level testing across age groups. Further investigation is required to establish the efficacy of aquatic competencies as a drowning prevention intervention, as well as exploring the relationship between aquatic competencies and age-related developmental readiness. In conclusion, early evidence suggests aquatic competencies can help to reduce drowning.