Four rules fix almost everything, and none of them requires buying anything.
Water absorbs red light first, then orange, then yellow. By five metres almost everything red is gone, which is why untouched underwater photographs look blue. That single fact drives all the advice that follows.
Get close. Then get closer. Every centimetre of water between the lens and the subject removes colour and adds haze, so a fish photographed from two metres will always look worse than the same fish from forty centimetres. Most underwater photography problems are distance problems.
Shoot upwards where you can. Pointing the camera slightly up puts the sun behind your subject and gives you a lit blue background instead of a grey seabed. Shooting down at coral is the most common composition and the least interesting one.
Pointing the camera slightly up puts the sun behind your subject and gives you a lit blue background instead of a grey seabed.
Do not use the flash on a phone — it lights the particles between you and the subject and produces a snowstorm. Shoot in the middle of the day when light penetrates furthest, hold your breath for the shot to stop the swaying, and fix the colour afterwards: raising warmth and reducing blue in any free editing app recovers most of what the water took.
