What is the color of water?
Water may appear crystal clear in a glass or from the surface but it's actually blue. The more water there is, the deeper the blue. So, I custom white balance for my underwater shoots. My cameras, even the ones that have an underwater white balance setting don't seem to get it right. If you do not have a camera that can custom white balance try using a pink/rose colored filter on the lens.
Two ways how I get my CWB:
If a camera can shoot in RAW the blue can be edited out in post but I like to get it as close as I can SOOC, straight out of camera. It saves time in post and it's safer, I know I got the shot and I can show my client straight from the back of the camera. And since many underwater cameras do not have the option to shoot in RAW, yet, knowing how to custom white balance for natural light underwater photography can make or break an image.
Eva Creel Photography