UNDERWATER PHOTOGRAPHY DEMANDS A LOT of dedication and practice. Many divers find it difficult enough to produce good results in tropical waters, let alone considering colder temperate waters as a studio.
     Our home waters might not always present perfect conditions, but limit yourself to those perceived ideal circumstances and you miss out not only on some fantastic subjects but also on the opportunity of improving your photographic techniques.
     Master the principles which produce good images in temperate waters, and your next trip to the tropics will be far more productive and less frustrating!
     So can these elusive techniques for producing good images in British waters be easily mastered The answer is yes.
     In British waters light levels are normally low, visibility can be poor and the water is often turbid. It can also be very cold, so one of the first objectives is to ensure that you are using the correct equipment to keep warm during the dive.
     If you are cold and uncomfortable, its not easy to concentrate on photography.
     A drysuit is therefore almost essential, and you should be familiar and experienced with the techniques required to use one. You dont want to be thinking about your diving, but free to apply your mind to photography.
     You also need to consider the conditions likely to be encountered under water and how well you can cope with them. If you are used to diving in calm tropical waters, rougher conditions and strong currents are not going to be productive and could even be hazardous. There are of course some subjects which emerge only with a little current, but unless you have experience with diving in these conditions, it is best to pick sites which will offer calm, slack waters and shelter from wind.
     One of the essential rules in underwater photography is to minimise the amount of water between lens and subject. In adverse conditions it is even more important to get as close as possible, and this can be achieved only by using the correct equipment.
     Lenses which would be considered extreme on land are the workhorses of underwater photography and we will generally find ourselves photographing either small subjects in close-up or large subjects and scenics at as close a range as possible. So regardless of which type of camera system you choose, your equipment inventory needs to include both macro lenses and a superwide-angle lens, which will allow you to get a lot in the picture when focused only a few inches from your subject.
     My definition of superwide is an angle of view of no less than 90, which equates to the 15mm on a Nikonos, 16mm on the Sea & Sea and 20mm on a housed SLR system. The wider the better, and perhaps the best tool of all is a fisheye lens, which gives a whopping view approaching 165.
     Superwide-angle lenses are available for both the Nikonos and housed SLR systems. For macro the choice depends on your camera system Ð for the Nikonos you will need extension tubes; for the Sea & Sea macro lenses/diopters (which fit to the front of the camera lens); and for SLR users a range of macro lenses is available in various focal lengths.
     Suspended particles in the water can degrade the image in two ways. First, they absorb and scatter available natural light, which will give the image a soft, foggy, out-of-focus appearance which will of course degrade further with increased distance from the subject.
     Second, when we add artificial or flash light to the picture, these particles can reflect light back to the camera to look like a snowstorm in the final image, otherwise known as backscatter.
     These conditions occur in abundance in UK waters and, you might think, present an impossible situation, but both can be overcome by a combination of getting closer and controlling the direction from which the subject is lit.
     As a general rule, you dont point your flashgun directly at the subject from beside the camera, because this normally results in a blizzard of reflected light. Instead, aim the flash at an angle from the side or above, so that the reflected light from the particles doesnt go towards the lens.
     This reduces backscatter and results in an apparent improvement in water clarity in the final image. Once you have mastered this simple technique, you will begin to view turbid-water photography much more favourably.
     The most natural-looking wide-angle images are those with a mixture of ambient and artificial light.
     When you are dealing with low light levels, this balancing of the two light sources is more difficult but can be achieved in three ways.
     First, you could select a faster film speed (perhaps 200 or 400ASA), which will allow you to capture the natural light with a reasonable aperture and shutter speed. The downside to this choice is an increase in the grain size in the final image, which may not be acceptable.
     The second choice is to open up your aperture, perhaps to its widest setting, but this will limit the depth of field in the image, which also makes focusing more of a challenge with the Nikonos and Sea & Sea cameras.
     The third choice is to slow the shutter speed down to a point at which you can still use a reasonable aperture of, say, f8 but also be able to collect some of the natural light in the background to balance the exposure.
     Shutter speeds in the range of 1/30th to 1/8th or even half a second can be used effectively with a little practice, but you will be able to use this option only with a housed SLR, as the slow speeds on the Nikonos and Sea & Sea are limited to 1/30th of a second.
     You might think that a shutter speed this slow would lead to blurred pictures, but remember that we are working close to the main subject, which will be exposed and frozen by the flash while the more distant background is illuminated by the natural light.
     If you have a moving subject in the foreground, perhaps a fish, you could choose to use rear curtain synch, which fires the flash just as the shutter is about to close.
     Again, this function is available only on current auto-focus SLR cameras, but it will ensure that any movement in the flash-illuminated subject will appear as slight blurring behind it, giving an impression of movement. Coupling this balanced lighting with close focusing on the main subject in your picture gives a more realistic feel to the image, increases perspective and also gives the appearance of far better visibility than might have prevailed at the time.
     Another advantage is that the dreaded backscatter shows up less against a pale green background than the dark one which would result if you illuminated the picture with flash alone.
     Another way of increasing the level of natural light in your wide-angle images is to work as close to the surface as possible. Even when visibility is poor, light levels in the first few feet of water will be far higher, allowing an acceptable combination of shutter speed and aperture.
     There are many suitable subjects on the reef-top close to the surface, and further offshore you may encounter jellyfish and much larger subjects such as basking sharks. Adding a diver to shallow-water pictures will enhance an image and can convey a message of exploration of the underwater world, perhaps at the beginning of a dive.
     You might also consider working half-in and half-out of the water, which is a very effective technique close to the shore, or even in large rock pools. Another technique to consider is shooting silhouettes, a simple option which can produce striking images.
     British waters are full of colourful subjects which make wonderful macro and wide-angle images, but as with any location you must know where to look for your subject and a little about its behaviour to make each dive a success.
     It surprises me how often divers will consult a stack of marine-life guides when diving overseas but rarely look at one for British waters. There are several excellent guides available which not only identify species but also describe their habitat and feeding habits.
     Armed with this information, look first for habitat and then for the subject. Nudibranchs, for example, are quite small in British waters compared with their tropical cousins, but many are no less colourful, and often missed on the reef.
     Knowing that they are most active in early spring, and that particular species might feed on bryozoans, hydroids or sponges, will help you spot these little critters more often and help you focus your dive on a particular subject.
     Other colourful close-up subjects include anemones, cup corals, decorator crabs, squat lobsters, prawns, flatworms and cowries.
     Our reef fish may not sport the vibrant colours of the coral species, but there are several very colourful and co-operative species which make excellent subjects.
     Who can resist the smiling face of a tompot blenny, the striking blue and orange livery of a male cuckoo wrasse or the intricate pattern of a corkwing wrasse These species are all inquisitive and will let you come close enough to take a sharp, well-lit shot if you are patient.
     There are also weird-looking john dories, lumpsuckers, monkfish, plaice and topknots, dragonets and a number of other semi-sessile species which are easy to approach closely. In the summertime you might also find cuttlefish and octopus, which are amazing creatures to observe and will often come close to the camera if you are patient with your approach.
     For wide-angle photography, a broad range of colourful subjects can be found on the reef or on the many wrecks around our coastline. The secret is to get as close as possible and view the subject with an upward angle to gather as much of the available light behind the subject as possible.
     When conditions are bright, try to include the sun in the shot, just as you would in warmer waters, or perhaps experiment with silhouettes of the kelp, part of a wreck or perhaps a diver.
     Sponges, dead mens fingers or brightly coloured anemones make excellent foreground subjects, or you can look for larger marine life to be the focus of attention, such as a spider crab picking its way over the reef, or a small school of fish around a wreck.
     The secret of good photography in British waters is to learn to assess the prevailing conditions, recognise the limitations they will impose on you during your dive, and then work within them, using the correct mix of equipment and techniques.
     Planning your photographic forays in this way and then adding a little research into the subjects you might target will dramatically improve your chances of success.
     Dont be too ambitious with your choice of dive site, either.
     Beach dives are often the best choice, as they are normally sheltered from strong current and offer shallow waters for long dives, with an abundance of subjects from which to choose.
     Joining a boatload of non-photographers to reach an offshore site doesnt always work well, as you will be constrained by their dive plan and could find yourself struggling with current.
     Take things slowly. Concentrate on finding only one or two subjects during the dive and then devote enough film to each to vary the lighting angle and exposure to ensure that you get two or three good shots worth keeping.
     When you experience disappointment, try to analyse what has gone wrong, rather than simply binning the shot, and then try again with a similar subject to ensure that you can get it right next time.
     This patient approach will improve your success rate in home waters and also put you in the loop far quicker when you invest in an overseas trip.
     Approaching British underwater photography in this way may even save you the cost of a few plane fares. Success is addictive and you could find yourself pining for those idyllic tropical waters less and less!

Colours in Britain can rival those of the tropics but you must go wide and get close to make the most of them
Some UK nudibranchs are as colourful as their tropical cousins and almost as big. The flamboyant Lomanatus reaches 5cm in length, but can be difficult to spot among the sea firs on which it feeds
Plankton blooms in spring and summer attract filter-feeders such as this compass jellyfish. In some years they can be very numerous and you can see dozens in a small area
Stay shallow with a wide-angle lens and make use of all the available light. Use just a touch of flash to restore colour and avoid the dreaded backscatter
Scorpionfish blend well with the reef, just like their warmwater brethren, but will often produce a surprising range of colour when illuminated by flash
The biggest fish in our seas, the basking shark, makes a brief appearance in the early summer to feed on plankton blooms. Use a wide-angle lens with available light, and a wetsuit and snorkel to keep up with it!
Monkfish or anglerfish are an increasingly rare site in our waters due to over-fishing. Once found they make striking subjects, but watch out for those teeth!
Dead mens fingers are a coldwater soft coral and come in a variety of colours, ranging from white, red, orange and yellow. You can enhance colours by adding a warm-up filter to your flashgun, but be careful not to overdo it, or the shot can look unnatura
We have our own symbiotic species to compete with the tropics. These little spider crabs can be found in the arms of the snakelocks anemone throughout the year, but are most prolific in the summer months
The detail of many marine creatures makes excellent macro subjects, such as this shot of the arms of a featherduster worm
Topknots are found on the rock surfaces of the reef, often upside-down in the cracks and crevices. They have good camouflage but make very patient subjects once discovered
Sometimes visibility is good offshore, but even so you must select an upward camera angle to ensure you gather as much of the available light as possible
The only stony coral we have in UK waters is the Devonshire cup coral. If the visibility is poor, you can add a tropical feel to your macro shots by adding some coloured backlighting with another flashgun
Look for splashes of colour in what might at first seem to be a dull landscape, then get close (below) to make the most of it