Little is known about the effect of clothing on water survival competencies such as swimming and floating in the prevention of drowning. In the first phase of a project entitled Can You Swim in Clothes?, ways of measuring swimming speed, endurance, and floating with/without clothing were explored. Physical education students (n = 12) with known water proficiency completed a 25 m sprint swim, a 5-min swim, and a 5-min float in swimwear and then repeated these tests a week later in clothing. Wearing lightweight clothes significantly reduced swimming speed (33%) and reduced swim endurance (28%) but no significant deterioration in flotation was found, irrespective of age or sex. Greater depreciation was noted in the sprint swim for those who self-reported low water competency. Reasons for this performance change are discussed and ways of applying the protocols developed in this initial phase of the project to other populations, especially those with less water competency and high-risk groups, are recommended.