Shallow water black-outs (SWBs) occur in all areas of the Department of Defense during training programs throughout the pipeline as well as in operations. Victims of SWBs usually lose consciousness within 15 feet of the surface, where expanding, oxygen-hungry lungs of breath-hold divers literally suck oxygen from their blood. SWBs are particularly frequent in environments that induce overexertion or self-induced breath holds. Hyperventilating adds very little oxygen to an individuals reserve, forcing carbon dioxide out of the lungs. Carbon dioxide is the trigger to the brain to breathe. Aquatic skills and water confidence training is a combat proven process and is an inter-service performance standard. This training however, is accompanied by certain levels of inherent and historical training risk. Trainee hypoxic episodes and shallow water blackouts are a common byproduct and are an assumed known constant during aquatic confidence training. The purpose of this effort is to develop and validate a heart rate and SpO2 sensor for real-time monitoring during water confidence training. Success in this program will reduce the probability of trainee fatalities.