The use of inertial measurement unit (IMUs) sensors in competitive swimming movement analysis has become increasingly popular but has not been applied to measuring water competencies related to drowning prevention. This study explored the potential use of IMU sensors in three simulated water competency activities in a pool environment. Participants were a subset (n = 12) of a cohort of students (n = 37) taking part in the Can You Swim in Clothes? project. Participants undertook a swim for speed test over 25 m, a distance swim of 5-min duration, and a flotation test, also for 5 min, wearing swimwear and again in lightweight street clothing while wearing an IMU to measure leg acceleration forces. Results showed that clothing impeded swimming sprint speed and distance but not flotation. Authors suggest further research with regard to IMU placement, appropriate survival activities, and measurement protocols and recommend the need for expanded future IMU use.