Chromatic adaptation in the underwater environment.

The effects of human visual chromatic adaptation underwater are usually reported in subjective terms. The present study aimed to generate data that could be discussed within the internationally recognized CIE color metric. Adaptation was assessed in two underwater environments (blue and green backgrounds). Divers were required to color match stimuli using either a Burnham-type colorimeter or the Munsell Limit Color Cascade. Comparisons of the chromaticity coordinates of matches made in air and underwater with those defined by color and luminance meters revealed an increased sensitivity to wavelengths approximately complementary to those of the background. Laboratory simulations of the underwater environments broadly replicated the field results. The data allow comparisons with complex mathematical models of chromatic adaptation that have been derived from orthodox experiments. The data might be helpful in quantifying the limits of human visual performance underwater.