Now I'm no video expert, though I do my fair share of working with HD, SD, and CrapD files. But people, PLEASE do yourself a favor. If your camera has Auto White Balance, turn it OFF. And if you can't turn it off, Ebay your camera!
We all know that trying to white balance your camera to work underwater is something of a crap shoot. As you swim up and down in the water column, the "balance" of the light changes. The thing is, with a constant white balance, this can generally be corrected scene to scene in post. When auto white balance is enabled, the camera responds by changing it's idea of what is white and what is not. And usually it's basing white on the brightest image on the sensors. So you swim by a cream colored rock, that's now white. Your buddy flashes his dive light to get you to come look at something, now that's the new white, etc. Instead of correcting scene by scene, you're correcting 3-10 seconds at a time.
Turn it off!