Absolute Distance Perception Underwater and Improvement through Training

A series of experiments was performed to obtain direct estimates of absolute distance under water, and to determine if judgment accuracy can be improved through training. Distance was underor over-estimated, depending to a large extent on water turbidity, which increased the magnitude of judgments. Also, whereas the power-function exponent for distance estimation in air was slightly less than 1.0, exponents in water were greater than 1. 0 and increased with increased turbidity. Divers quickly learned to make accurate judgments when they were informed of the correct distance after each of a series of judgments, but training did not adequately transfer to another body of water when there were large differences in turbidity. The results have implications for the training of divers.