One of the biggest differences of photographing people (or anything, really) underwater is how colors appear – and by that I really mean disappear. I’m a photographer and not a scientist but the basic concept is that light is absorbed as it moves through water and colors begin to fade after only a few feet. Red’s longer wavelengths make it the first to go and I took the series of images below to show how drastic the shift is from one side of a small swimming pool to another. These are essentially straight out of camera (resized and converted to jpg only) and taken at 18mm on a full frame D700. Notice my foot in the second frame which gives you an idea of how close I was to get such good colors and perspective for the other images taken from further away.