The purpose of this study was to develop a prediction equation that could be used to estimate maximal oxygen uptake (VO₂max) from a submaximal water running protocol. Thirty-two volunteers (n =19 males, n = 13 females), ages 18 - 24 years, underwent the following testing procedures: (a) a 7-site skin fold assessment; (b) a land VO₂max running treadmill test; and (c) a 6 min water running test. For the water running submaximal protocol, the participants were fitted with an Aqua Jogger Classic Uni-Sex Belt and a Polar Heart Rate Monitor; the participants’ head, shoulders, hips and feet were vertically aligned, using a modified running/bicycle motion. A regression model was used to predict VO₂max. The criterion variable, VO₂max, was measured using open-circuit calorimetry utilizing the Bruce Treadmill Protocol. Predictor variables included in the model were percent body fat (% BF), height, weight, gender, and heart rate following a 6 min water running protocol. Percent body fat accounted for 76% (r = -0.87, SEE = 3.27) of the variance in VO₂max. No other variables significantly contributed to the explained variance in VO₂max. The equation for the estimation of VO₂max is as follows: VO₂max ml.kg^-1·min^-1 = 56.14 - 0.92 (% BF).