The body core temperature must be maintained within a narrow range in all types of environments, and neoprene insulating capacity is usually used to minimize heat loss in the water. The thickness of the neoprene sheet is highly correlated to the thermal resistance of neoprene and can be precisely measured. However the physiological response of the diver will depend on several factors besides the thickness of the neoprene wetsuit: water temperature, current, body movement, body size, body fat, and fit of the neoprene suit. Previous experiments included measured differences in diver’s body temperature with ingestible capsules and skin temperature patches, as well as measurement of heat loss of a human diver and thermal mannequin. This paper compares the thermal resistance of nine different commercially available neoprene measured with a hot plate device, and the heat loss of a person immersed in water with the same nine neoprene suits measured with a thermal camera. The relationship between the obtained measurements is described by suitable statistical models.