In Florida you can go snorkeling in water that is clear enough to take pictures. That's where these ones were taken. I didn't use my usual DSLR for these though since the waterproof casing would cost more than the camera. Instead, I borrowed a friend's point-and-shoot that had a waterproof case.
All of these underwater pictures had a very strong green cast to them. I understand this has to do with the white balance formula in the camera being affected by the light-filtering effect from the water. As a result, these pictures needed some significant help from Photoshop. Regardless, I think they look pretty good.