In order to make better pictures underwater, I’m not only fitting out a used case for my 5D, but I’m also learning a new technique for developing the underwater raw photos in Lightroom to better reflect what they should look like.
Normally, pictures you take underwater are extremely blue:

Previously, to fix this, I would import the file into Photoshop, run a custom action which would add a red layer, do some magic and then, I’d save the PSD file and adjust it some more and maybe it would look okay:

Now, I don’t know about you, but that looks a bit strange what with the purple water and all. So, I’m now working in Lightroom using a technique that uses white balances and black levels to make corrections. It’s non-destructive, doesn’t require a second PSD file and is very flexible. Much faster as well. Here’s that same picture with the new method:

Blue water, proper skin tones, over all, much better.