Hidden Depths – the essential kit of deep sea diving Photographer Monty Halls shoots the vital equipment that facilitates his deep-sea exploration

In 2013, Monty Halls led a team of specialist divers on a six-month project to attempt to answer some of the lingering mysteries in diving – a series of investigations that took them to Egypt, the Great Lakes, Namibia and Japan. Many of the dives required operating at depth, beyond the range of normal recreational diving equipment; therefore specialist gear was required.

“Several dives undertaken by the team meant using mixed gas and highly complex planning – we were venturing into a twilight world where the margin for error was minimal. The deep sea is a hostile environment, and gear failure had massive implications, so we had to be meticulous throughout the project. We relied very heavily on our kit, and I’m happy to say that it performed magnificently. I think on our planet today, to find real mystery, you don’t go up, you don’t go sideways – you go down. This kit allowed us to do that.”

O’Three diving drysuit
DRYSUIT: Water conducts heat about 25 times faster than air, so even in tropical water you’ll get cold eventually. At depth, hypothermia can be a real issue, particularly in the Great Lakes where the water temperature was four degrees Celsius. In these waters, without some sort of thermal protection your survival time would be measured in minutes, so I used an O’Three drysuit (and a heated vest underneath) to stay toasty. It can take a long time to find the right suit so, once you do – just like a good barber or a brilliant mechanic – you are loath to change it. This suit will be with me for some time.
Diving torch
TORCH: The ‘photic zone’, the deepest point where any ambient light exists, extends only a couple of hundred metres, even in crystal-clear tropical water, so having some sort of illumination at depth is absolutely key. This was my primary torch, I also had a smaller back up, should this one fail – which it never did, I hasten to add. Part of its reliability stems from its battery – the large cylinder connected by an umbilical. This meant that, even with our longest dives requiring extended decompression stops, I was never left suspended in the darkness – an unnerving sensation to say the least.
Diving fin
FINS: I always think you can tell a great deal about what a diver has been up to by looking at their fins; the network of scars, nicks and scratches tells a tale of its own, and is as unique as a fingerprint. They are one of the elemental things I love about diving: you are weightless, can move in three dimensions, and can glide through a strange world propelled only by your own muscle power. Even after 30 years of exploring the marine world, the first fin kick on any dive has never lost its magic for me.
Sentinel diving rebreather
REBREATHER: A rebreather recycles exhaled air, allowing the diver to stay underwater for longer than standard open-circuit diving equipment – essentially you are breathing in and out of a bag. The snag with this is that eventually you’ll pass out unless CO2 is filtered out, and enough oxygen is introduced to keep you conscious. This is a Sentinel rebreather, and it’s a truly wonderful piece of kit. There are no bubbles with a rebreather of course, so you explore a silent world, with only the occasional beep of electronics from the kit and the whisper of oxygen being introduced – two very reassuring sounds indeed.
Hugyfot diving camera underwater housing
CAMERA IN UNDERWATER HOUSING: Saltwater and electronics are poor bedfellows, and yet we needed to record our dives for the television series we were filming. This is a Hugyfot housing, engineered from a single block and snugly designed so it can be used with one hand. It is a stills setup, as opposed to a filming camera; the fish eye lens with wide dome port allowed us to take some glorious images of caves, wrecks and caverns. It was always a sweet moment to lift it out of the sea though – I’ve never quite lost that fear of killing cameras on a dive (I’ve murdered a few in my time).

Words: Monty Halls
Photography: Greg White

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