Underwater photography: a beginner's guide - in pictures

One of the challenges of underwater photography is that when shooting at depth you lose a lot of colour; red is the first colour that water absorbs. Staying shallow and shooting up, and against the blue, will enhance the pictures, keep them brighter, and help to pick out those reds. Always keep a respectful distance too. Photograph: Susan Smillie/Guardian

The most important skill to master is buoyancy control – not only for getting good steady shots, but for protecting the reef. Consider what the dive site is good for, set your objectives and look around for a perfectly composed shot. A striking subject, such as this unicorn fish, prominent on the reef with a blue-water background, was just the ticket. Photograph: Susan Smillie/Guardian

As with any wildlife photography, there’s always a bit of luck involved. I was in the right place when this school of barracuda passed. Keep close and snap away – and don’t use the zoom, it doesn’t lessen the amount of water between the camera and subject and will just show up particles underwater. Photograph: Susan Smillie/Guardian

One of the rules of scuba photography is to always shoot on the same level as the subject, or from below, so the image will have greater depth and you’ll make the most of the light. There may also be some snobbery among divers – shots taken from above are often dismissed as snorkelers' pictures. But, of course, rules are made to be broken, so take the shot that pleases you, like this one. Photograph: Susan Smillie/Guardian

Get close to your subject – but not too close! I took several shots of this moray eel at newly reopened dive site, East of Eden, only to discover while researching afterwards that this was almost certainly the resident “Scarface”, infamous for biting a diver’s thumb off. Photograph: Susan Smillie/Guardian

There’s always one shot every photographer wants to get. This was mine. It’s not perfect but I’m pleased with it. A tip from pro photographer Nick Shalcross reminded me that turtles need to surface every 20 minutes, so I hung around with this one for about 17 minutes and hey presto! Photograph: Susan Smillie/Guardian

Focus on composition: what do you want in the frame, and what should be left out? Get close and tightly frame the shot. Eye contact is important too; I'm immediately drawn to the fish that’s looking at the camera in this photograph. Photograph: Susan Smillie/Guardian

Choose backgrounds that are going to show your subject most clearly. A lot of coral is too detailed and colourful to really work as a background so look for simple clear crisp backdrops if you can’t get animals against the blue. There's a classic case of 'fish bum' in this shot though, which may have been better cut out. Photograph: Susan Smillie/Guardian

This lionfish has poisonous spines and can be quite territorial, so care is needed. Sometimes you can’t get the clear background you'd want but if it's an interesting animal, it needn't spoil the shot. Do the best you can without putting yourself in harm's way. Photograph: Susan Smillie/Guardian

Breathing underwater is noisy and scares wildlife, but you absolutely cannot hold your breath, so keep it steady and use it. Inhale or exhale to go up or down slowly to the right level. Breathe in to take your final shot to come up and over your subject, as I did with this lovely little boxfish. Photograph: Susan Smillie/Guardian

Some scenes might not win you next year’s Oceans of Life competition, but that’s not what photography is about for amateurs like me. I like the way this little batfish just seems suspended in mid-air (they're notoriously hard to get close to without showing tail). Photograph: Susan Smillie/Guardian

Some fish are friendlier and braver than others. I had a soft spot for the comedy look of these titan trigger fish, with their strange fabric-like appearance and button eyes, and their curious nature that allowed me to get close up. But they are quite feisty territorial fish so care is needed. Photograph: Susan Smillie/Guardian