Lights or Custom WB

Has the ability to use a custom white balance at depth make lights unnecessary? Especially with video. I found that when I've use custom WB the video looks great, and stills don't have backscatter. Thoughts?

Whilst I agree that a custom WB can make all the difference to both stills and video underwater it won't remove the need for lighting unless you are shallow enough for ambient lighting to suffice. You will also be able to take advantage of your camera's iso performance but again this will have limitations on dull days or at any real depth, especially for macro when you will almost always need lights to allow apertures required.

I was afraid you'd say that : ).

Turn your lights on and white balance then, not before. Keep in mind the distance your subject will be from you as well as an awareness of where the sun is. Each time your lighting conditions change, re-white balance. I WB upon my white fins which will always be about 4 feet from my cam. WBing on a slate in front of your port does not provide a realistic lighting condition in my opinion.

Steve