The capacity to maintain the airway through buoyancy control when immersed in water is critical in preventing drowning (Stallman, Moran, Quan & Langendorfer, 2017). In this first phase of the Can you Float? study, perceived and real unsupported flotation competency of a group of students (n=37) with known water proficiency was examined. Using a modified version of Borgs Rating of Perceived exertion (RPE), participants were asked to estimate exertion levels before and after a practical test of five stationary floating tasks of increasing difficulty ranging from treading water to motionless floating. Most participants (82%) were able to tread water for 2 minutes but only one third (31%) could perform a motionless float for the same duration. In all tasks students underestimated the level of exertion required. Reasons for, and implications of, this underestimation are discussed and recommendations for the teaching of unsupported flotation competency in water safety programs are made.