The difference between amateur and professional diving equipment is as marked as the difference between agricultural equipment and what you might buy at Homebase for your gardening requirements.
Professional divers tend to be muscular lads with a healthy appetite for food, drink and air. They don’t go under water to swim about looking at fish. They are there to work, and the work tends to be very physical.
They don’t boast about how little air they used. They boast about how much work they got done. They’ll be supplied with however much gas they need.
The Divex 960 MIL regulator is designed in Stockholm for use in extremely cold and hostile environments, and the Swedes know about that. Its unusual design features are all aimed at preventing malfunction through freezing.
Working divers tend to be not too careful with the kit they use. Why should they be They didn’t pay for it. So a professional item of diving equipment like this is built to a standard of robustness rarely seen in amateur dive gear.

First Stage
The set-up sent to me to try was rigged with a second stage on a 2m-long hose, an octopus and a Divex pressure gauge, weighing around 2kg in all. It has a brute of a first stage with two high-pressure and six low-pressure ports arranged around a fixed barrel.
One of the lp ports comes with an over-pressure valve plugged in. Others are suitable only for the over-sized bore of an intermediate-pressure hose.
Water has free access to the ambient-pressure-sensing diaphragm through large holes
in the cap. These reveal the big spring that resists the water pressure and conducts heat from the water to the colder gas passing through the regulator.
The second stage is an upstream piston-type design with a unique balancing chamber that ensures that the two stages are always in balance during both inhalation and exhalation phases.
Unusually, the inter-stage pressure at 5bar is lower than the 8 to 10bar more normally encountered, so the large bore of the intermediate hoses needs to carry enough gas. The first stage is finished in matt black.

Second Stages
Second stages are finished in matt black too, and they’re huge. Their fronts measure more than 8cm in diameter. Big holes allow water to flow in easily, and the purge button is unmistakable.
Working divers tend to spend a lot of time stationary, and don’t want to be irritated
by exhaled gas obscuring their view.
The exhaust-T of each second stage is a massive 13cm wide, so expired air bubbles are directed well away from the diver’s face.
Airflow is adjusted to personal requirements by moving a lever inside the second stage via the mouthpiece.
Because the second stage has an upstream design, the over-pressure valve is on the first stage. It also features a mouthpiece unique to Divex, one that takes into account one of the greatest flow restrictions – the diver’s front teeth.
Both first and second stages are “venturi force boosted”. This increases with depth.

Cold Water Performance
There are no anti-freeze caps or any other supplemental fittings. Massively wide-bore hoses and low intermediate pressures lead to reduced air speeds while still maintaining enormous flow rates.
The 960 MIL regulator components are designed to work together as a system, so it would be a mistake to try to substitute more conventional hoses. If you need this sort of performance in the environment for which it was designed, there isn’t too much choice.

In The Water
It was summertime, so I had to content myself with trying this regulator in an inland UK dive site rather than under the conditions for which it was designed.
When I last tried a similar type, at least there was ice on the lake, but this time it was almost sub-tropical. So I abandoned that idea and went for depth instead, in the Red Sea.
Suffice to say, there is nothing subtle about the way this regulator breathes. The cracking pressure was such that there was a slight hesitation when I pulled on it, and then it was like the roof blowing off in a storm. It was nothing or everything. This could be adjusted between dives by moving the lever inside the second stage accessed via the mouthpiece but it’s not something that you can easily do once you are under water with it.
After about half an hour under water, the massive flow of air was tending to make me gag and retch. A lot of it was getting into my stomach.
It got so bad that I even contemplated inhaling the seawater instead of letting another dose of hurricane down my throat.
Of course, I would have drowned, but that’s how I came to regard the threat of the next inhalation. But having said this, I’m aware that there will be people who like this sort of thing, and its appeal may not be confined to hard-breathing commercial divers.
As I looked past that massive second stage, I reflected that this was the difference between the catering-style dough-mixer I’d seen in the galley of the wreck of the Umbria, and a Kenwood Chef.

PRICE £557 (basic regulator), £733 (complete as tested)
FIRST STAGE Piston-type (upstream)
PORTS Six (including moveable over-pressure relief valve)
DIVER GUIDE width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100%