Blackwater Diving: Photography Tips, Techniques & What to Expect

Alex Mustard focuses on a diving style that is rapidly growing in popularity, and one that will challenge underwater photographers – blackwater

Photographs by Alex Mustard

Tiny phytoplankton are the powerhouse of the ocean food web. These single-celled plants proliferate in sunlit upper layers in astronomic numbers and account for more than half of all photosynthesis on Earth.

ny phytoplankton are the powerhouse of the ocean food web. These single-celled plants proliferate in sunlit upper layers in astronomic numbers and account for more than half of all photosynthesis on Earth.

The challenge comes for the grazers that want to eat these plants. Because if you are a small fish or crustacean, just the right size to be able to feast on single celled algae, you are bite-sized for many types of fish, squid and other predators.

So while there is lots of plant food near the surface, it is a dangerous place to be during the day when your predators can easily spot you.

Nature’s solution creates one of the most spectacular, but rarely seen, wildlife events on the planet – the largest movement of animals there is, known as the diel vertical migration. With aching bellies, these tiny creatures head for the surface each evening, migrating hundreds of metres despite some having bodies best measured in millimetres.

The migration concentrates life in the upper layers each night, before they return to the depths at dawn, and it provides one of the most fascinating diving experiences – blackwater.

Blackwater is a type of night dive conducted in open water. A rope is hung from a buoy and bright lights are attached to it at intervals which draw in the plankton and provide a reference for the divers.

As a diver, you slowly circulate around the line, checking out every object in your torch beam, hoping it might be a pelagic octopus, a larval crustacean or a juvenile fish, with outrageous adaptations to living in open water.

You and the line might drift several kilometres during the dive, but since everything is floating along together, there is no feeling of current at all. Once you’ve got used to the idea, these are very relaxing dives, where you feel like you are suspended in a thick soup of life, rather than diving in open water.

The reason these dives are fascinating is just about every species in the sea has a pelagic larval stage. As a terrestrial species it is natural that we consider our biology and that of the species around us as normal.

But in reality, we are the outliers for life on this planet! Most species never meet their children and look nothing like them, either.

In the ocean, eggs hatch and don’t immediately settle down to life with the adults, but instead grow on and disperse as part of the plankton.

Here, the demands of life are very different, so they usually look very different to the grown-ups we’re familiar with. Larval stages are often more translucent to keep them hidden and with a multitude of appendages that may help keep them afloat or disguised.

This is the draw of blackwater, the chance to photograph alien-looking creatures all posed perfectly on an attractive black background.

The set-up, settings and technique for blackwater photography are pretty straightforward. I always try and get my camera as neutral in the water as possible and dive with both a focus light and spotting torch on a lanyard on my left wrist.

Shorter focal length macro lenses are usually favoured, because they are easier to aim and focus, and shots can always be cropped a little if needed afterwards.

Almost all blackwater shots are taken with the same basic settings, using a closed aperture to maximise depth of field, I usually set to f/18. I tend to vary ISO the most on dives, dropping it down for more solid, larger subjects and increasing for smaller, translucent ones, usually through the range of 200-640.

Most shots use a fast shutter speed to stop any torch light from ruining the exposure, but occasionally it can be fun to sometimes play with longer exposures and intentional panning to create trails from subjects.

Generally, we need plenty of strobe power, so I use powerful flashes and run them a couple of clicks down from maximum power to maintain a good recycle time.

I usually position them shoulder width apart, aimed in at the subject, as this crossed lighting tends to help reveal translucent subjects more clearly, as well as reduce the flare of shiny scales and eyes.

I would always prioritise getting the best illumination on the subject above worrying about backscatter. Backscatter can be cleaned from most blackwater pictures in justa couple of seconds in Lightroom.

While the technique of blackwater sounds very simple in theory, the challenge is actually delivering it on the dives. Remember that juggling flaming torches sounds simple when you describe it – just throw and catch each torch in order!

Most photographers find they need a bit of practice to get into the blackwater groove, so book a few dives and stick with it, the results will come.

It is a type of photography that rewards good diving skills, and the best blackwater photographers tend to be the best divers.

High levels of stability in the water allow you to closely approach a subject without disturbing it with your bow wave, and to accurately and consistently frame it, which isn’t just important for composition, but also to allow the autofocus to lock onto it.

I tend to keep things simple for the autofocus, by just using a single focus point, so the camera can concentrate on that.

Controversially, I’d suggest that one of the appeals of blackwater is that there is little to do creatively. You grow your portfolio by doing more, not thinking. Better shots come from finding better subjects and then shooting them with exactly the same technique.

This focus on searching for subjects pushes those primitive hunter-gatherer buttons in our brains and is highly addictive. Curiously, this also means that there is no shortcut to a blackwater portfolio, photographic inspiration cannot really trump just doing more diving.

Most experienced photographers feel on top of the technique after a couple of dives, and then very comfortable after ten or so blackwater dives.

Most who are struggling tend to blame their camera or hope that some magic focus mode others are using will save them. In reality, most struggle because other branches of underwater photography don’t challenge their diving skills like this.

If you are finding it a challenge, use your day dives to optimise your weighting and trim. I see so many divers, even very experienced ones, diving overweighted and while it usually matters littles, blackwater will punish you.

Blackwater diving has been taking place since in the 1970s, but it has become a more mainstream diving attraction in the last decade with the increasing popularity of underwater photography and the suitability of modern digital cameras to this type of shooting.

It is now available in many dive centres around the world and major hotspot locations are coming online all the time. Spend some time getting familiar with the creatures you are likely to see and with a little practice blackwater can add some stunning images to your portfolio.

FAQ: Blackwater Diving & Photography

Q: What is blackwater diving?

A: Blackwater diving is a type of night dive in open water, where divers use lights suspended from a buoy to attract plankton and pelagic creatures that rise to the surface during diel vertical migration.

Q: Why is blackwater diving popular with photographers?

A: Because nearly every ocean species has a pelagic larval stage, blackwater dives offer rare opportunities to photograph translucent, alien-like creatures against a striking black background.

Q: What equipment is best for blackwater photography?

A: Short focal length macro lenses, strong strobes, a focus light, and neutral buoyancy set-ups work best. Photographers usually shoot with closed apertures (around f/18) and adjust ISO for subject size and translucence.

Q: How do you light subjects during a blackwater dive?

A: Most divers use powerful strobes positioned shoulder-width apart and angled inward, which highlights translucent creatures and reduces glare from reflective scales or eyes.

Q: How difficult is blackwater diving compared to other styles?

A: It requires excellent diving skills and stability, as subjects are tiny and often delicate.

Q: Where can you do blackwater dives?

A: Originally started in the 1970s, blackwater diving is now offered in many dive destinations worldwide, especially hotspots like the Philippines, Indonesia, and Hawaii, with more centres adding it regularly.