To investigate if U.S. Navy diver training has an effect on physiological parameters i.e., heart rate HR and SpO2 levels, time of useful consciousness TUC, and cognitive performance during periods of normobaric hypoxia. Methods Each subject completed a helmet and aviator mask fitting, SynWin multitask battery training, a normobaric hypoxia symptom familiarization session, and a data collection session which consisted of simulated altitudes of 0 feet above MSL 0k, 18,000 feet 5,486 m above MSL 18k, and 25,000 feet 7,620 m above MSL 25k. Three separate two-way multivariate analysis of variance MANOVA were run for each simulated altitude with GRP diver, non-diver as the between-subjects variable were conducted for SpO2, HR, TUC, and SynWin composite score SCS data. Bonferonni corrections were applied as necessary to maintain a family-wise alpha of 0.05. Results The results of the MANOVAs indicated that USN diver training had no effect on Fg-SpO2, HR, TUC, or SCS for the 0k, 18k, and 25k exposures. Conclusions There were no significant differences between diver and non-diver physiological parameter measurements, TUC, and cognitive performance during any of the normobaric hypoxic exposures. The results of this study will help to validate the use of a 60 cut-point for SpO2 levels as one input for a physiological based definition of TUC. Future research should focus on developing a model that incorporates a 60 SpO2 cut-point, as well as changes in HR and blood pressure data that are based on the subjects individualized normative data.