A Shot in the Dark

BLACKWATER DIVER

A Shot in the Dark

Where once divers studied reef- or bottom-dwelling lifeforms, with the odd glance into the blue in hopes of spotting passing pelagics, on a blackwater dive you explore by night in open ocean, where most of the Earth’s biomass is concentrated. Text and photos by JESPER KJØLLER. Illustration by ALEXANDRA HUTH

1219 Blackwater main

Appeared in DIVER December 2019

A fish investigates a floating colony of tunicates.

Being on a boat on a moonless evening could have been serene, but the silence is disturbed by muffled club music from a distant party somewhere on shore. Deep disco rhythms seem strangely out of place in the black night, but in the Philippines they rarely miss the chance of a good fiesta.

The crew on our bangka prepares the blackwater rig – a weighted line with a buoy and strong lights attached. They work methodically, and it’s apparent that they've done this before.

We left the resort around sunset 20 minutes ago, and we arrive in Moalboal Bay as the tropical night falls.

The crew heave the finished rig out into the allegedly 500m-deep black ocean, and we wait. The line needs to “cook”, as they say. Leaving the rig in the water for half an hour before we jump in should ensure that the shine attracts the critters

The light rig serves three purposes.

Firstly, it entices the organisms in the dark ocean.

Exploring between the two cones of light on a blackwater diving session.
Exploring between the two cones of light on a blackwater diving session.

But because there must be loads of plankton and larvae in the water column already, even if we just dived with our own torches, the second purpose is to serve as a reference point for the dive – both for depth and orientation.

The third purpose is to make it easy for the boat to follow the floating divers and the line drifting with the current. As the divers are travelling at the same speed, the current is not felt.

Snowstorm

After the cooking, the boat slowly approaches the bright pool of light around the buoy supporting the line.

We jump in, and a crew-member hands me my camera.

The water is a pleasant 30°C, but I was advised to wear a hood to protect me from stinging hydroids floating around. I’m almost too warm, so I let a little water into my suit to cool myself down.

Exchanging quick OKs and thumbs-downs, we descend close to the line.

This is my first attempt at blackwater photography, so I don’t know what to expect. If a normal night-dive invokes your inner boogeyman, blackwater diving is probably not your thing. But for me, the dark, warm water has a strangely soothing effect, and I immediately go into the zone.

I let my eyes adapt to the conditions and look around to assess the results of the cooking. I see nothing.

Well, I see snow. Lots of snow. The powerful lights on the line create the same effect as headlights in a snowstorm, and I’m worried that I'll get nothing but backscatter in my images.

Then I remember my first muck-dive, many years ago in Lembeh Strait. I had the same “what am I doing here?” feeling, and tell myself to be patient.

I look around to orient myself. I swim further away from the strong glare of the lights on the line, and discover that it is better not to be too close to the light cones from the rig.

After a few minutes, I spot a small jellyfish the size of a coin. All right, game on!

I approach with care and try to take a few pictures. The first images are completely dark, but after some exposure adjustments and experiments, I begin to get a few acceptable shots and feel more confident. I can do this!

I look around for more subjects, but after another five minutes still get nothing but snow.

Jedi (K)night

Suddenly Felix, my reliable Filipino guide, signals with his light. He is

using a strong torch with a very narrow beam that cuts through the dark like a light-sabre.

I imagine the swooshing sound, and can almost hear the Star Wars fanfare.

He beckons me with his torch and points in the direction of … eh – what is that? With the magnification of my viewfinder, I suddenly recognise a well-known character – a juvenile flying gurnard the size of a little finger.

Felix is excited – after the dive he tells me that this is the first time he has seen one of these. Good start!

The gurnard is difficult to get in focus. It never really stops moving, but keeps descending in the water column.

I feel the pressure in my ears as I sink with the critter to keep it in the viewfinder. After some 30 exposures I hope that I have a few good ones, and let it go.

I look at my computer. 22m – oops! That’s a little deeper than we agreed before the dive.

I swim up to reunite with Felix.

He does his Skywalker impersonation again and points me towards another interesting subject. This continues for another hour.

Strategy

Argonauta nodosa, a paper nautilus – the white area shows where its iconic spiral shell is starting to form.
Argonauta nodosa, a paper nautilus – the white area shows where its iconic spiral shell is starting to form.

My blackwater dive has been arranged by Kasai Village Dive Resort on Cebu. It usually arranges these dives a couple of times a week, and to optimise the effort of preparation, it’s a two-dive outing.

We are served a delicious if primitive meal on the boat during the surface interval. The setting is pleasant, apart from that booming music.

I review my images, and feel better prepared for the next dive. The crew huddle behind me to get a glimpse – they are surprisingly enthusiastic, and I’m happy to be able to share the experience, because, after all, they have done all the heavy lifting. All I do is press the trigger.

I think back to the good old days before digital, when I would be limited to 36 exposures before leaving the water to change film. Even worse, I had no way of evaluating (or sharing) my images until I picked up the film at the photo lab after coming home.

The opportunity to analyse digital photos on the back of the camera while still in the field makes an enormous difference. I begin to get a good strategy in place for the next dive.

Focus

It’s all about focus. With exposure and framing you have a little post-production wiggle-room, but you have to nail the focus in the water. As always, if the subject has eyes, these are the main focal point.

Apertures in the middle of the scope of your lens is always a good compromise. Most lenses are sharpest in this range, and it is a good balance between depth of field and light sensitivity. I use my Nikon 60mm on f18 for most shots. Shutter-speed is 1/125th.

My strobes are set on fairly low power, to minimise backscatter and lower recycle time. The quick recharge allows me to shoot bursts of images in quick succession to hedge my bets.

If the critter is shiny and reflects the light too much, I compensate with a lower ISO, but I try to keep the rest of the settings fairly constant.

I have my strobes placed almost perpendicular to the lens to reduce backscatter and strong reflections in the shinier fish scales.

As soon as I have established a focus, I pull the trigger and fire a quick burst of shots – maybe five or 10 in rapid succession. I reframe, adjust focus and fire another round.

Most cameras allow you to assign a separate focus button (look for Back-Button Focus in your camera manual) and it is a great advantage not to have focus and shutter assigned to the same button, even if this is usually the default mode.

Most seasoned underwater photographers agree that a full-frame DSLR with a 60mm lens is the best option for blackwater photos. With a 100mm or 105mm lens, it’s just too difficult to focus.

And you can forget about using dioptres or wet lenses. With a modern full-sensor DSLR camera, you can crop the images if necessary to mimic the effect of longer lenses and dioptres, but I often managed to get close enough to enjoy the 60mm’s very short focus distance.

Transparent camo

Some dive operations tether divers to the line to prevent them straying too far.

This is a solution looking for a problem, and it would certainly limit my freedom of movement. If you need to be tied to a line, you probably shouldn't be diving in open ocean at night anyway.

If divers have solid buoyancy skills and good situational awareness, tether lines will only introduce other potential problems. It’s better to increase safety with a limited number of divers in the water with good, alert dive-guides.

Some creatures will seek the lure of the focus light. Almost like a deer in the headlights they freeze, not sure what to think about the approaching thing with flashing lights. Others dash off after the first shots, leaving you hoping that you got at least a few acceptable exposures.

The most difficult subjects are the transparent or translucent organisms that unfortunately make up a large proportion of these creatures.

Apparently being transparent is the best camouflage when there is no background. For obvious reasons, these creatures are difficult to get in focus and to light. You basically shoot right through them, and your lights are eaten up by the infinite darkness behind.

Be very careful when you approach the critters not to create a shockwave when you move forward.

Slow deliberate finning and no arm-swimming movements is the name of the game. My angled viewfinder was also a great advantage, because it is ergonomically easier to look through it and compose the image while staying in flat trim.

The party noise is slowly disappearing in the distance as we head back to the resort jetty, and I know one thing for certain. My first attempt at blackwater photography will not be my last.

The Vertical Migration

 An unidentified fish!
An unidentified fish!

Every night a great vertical migration takes place in every ocean. This mass movement rises from the depths to the surface, with most of the lifeforms on the journey so tiny that they are invisible to the naked eye.

With the zooplankton comes a variety of both pelagic and larval creatures to feed on the plankton and each other.

They swim up sometimes more than a kilometre, and return the same distance in the morning.

These animals are helping to offset carbon dioxide, so reversing some of the damaging CO2 emissions made by humans. By eating the products of photosynthesis at the surface and swimming back down, they shift a huge amount of carbon to the deep.

Most of these creatures are small planktonic crustaceans called copepods. But trillions of krill, jellyfish, shrimp, squid and other ocean residents join the voyage.

Ichthyoplankton, the eggs and larvae of fish, are mostly found in the sunlit zone of the water column.

The word plankton indicates that they cannot swim effectively, so drift with the currents. Fish eggs can’t swim, so are clearly planktonic.

Early-stage larvae swim poorly, but later-stage larvae cease to be planktonic as they grow into juveniles.

Fish larvae are part of the zooplankton that eat smaller plankton, while fish-eggs carry their own food supply. Both eggs and larvae are themselves eaten by larger animals.

Larvae that are the newly hatched young of oviparous fish are usually poorly formed, carry a large yolk-sac for nourishment and look very unlike juvenile and adult specimens.

Their larval period is usually only a few weeks, as they rapidly grow and change appearance and structure (a process termed metamorphosis) to become juveniles.

During this transition, larvae must switch from their yolk-sac to feeding on zooplankton, a process that depends on the density of their prey.

How Do You Attach a Jon Line? @BrentHollett #askmark #scuba

LET’S KEEP IN TOUCH!

Get a weekly roundup of all Divernet news and articles Scuba Mask
We don’t spam! Read our privacy policy for more info.
Subscribe
Notify of
guest

0 Comments
Inline Feedbacks
View all comments

Connect With Us

0
Would love your thoughts, please comment.x