This photo is from my analogue photo area. I took it in 1995 using a disposeable camera in an underwater housing from Ikelite along with an external flash.
If you plan to invest in an underwater housing for your camera I strongly recommend an external flash mounted to an extension arm. Using the internal flash of the camera will result in a photo full of bright, white spots. Those spots are sand and other usually invisible small particles floating around in the water. But as soon as you use a flash mounted close to the lens, the light emitted from the flash will be reflected by the floating particles directly into the lens. So it’s best to use an extension arm and mount the flash at a small angle so the light does not directly reflect into the lens of the camera.
It took my a while to stamp out and correct most of the floating particles with Apple Aperture [Mac App Store Link].