I’VE MADE NO SECRET in recent years that I like Atomic regulators. Why do I like them Because they are made to a cost-no-object design by guys who quit a scuba manufacturing giant because its bean-counters wouldn’t let them do it.
That said, in these difficult economic times we divers are as hard up as everyone else.
While those merchant bankers who are divers can still afford to buy themselves an all-titanium Atomic TX2, everyone else is left smarting at the price. So the guys at Atomic have looked at ways of making their products more affordable.
Using a cheaper material than titanium is an obvious answer. The Atomic Z2 has most of the same features as its expensive sibling, but is made, like most regulators, from chrome-plated brass, though with some titanium and stainless-steel components.
It is zirconium-coated for a tough finish. It is also slightly simpler, in that it has a fixed rather than a revolving turret for its low-pressure ports. A turret version is however an extra-cost option.

First Stage
The Atomic Z2 is a balanced piston-type design, with all the high flow-rate performance this implies. It has a high-pressure piston-seal system, in common with all Atomic regulators. This affords low maintenance thanks to the corrosion-resistant materials employed, and a long servicing interval.
What don’t I like Being a piston-type design, the Z2 relies on being filled with an anti-freeze liquid retained by a rubber band. I’m not confident that this is the best solution for use in the sort of cold fresh water we encounter at inland dive sites in winter.
All Atomic regulators are supplied nitrox-ready for mixtures up to 40% oxygen. It’s down to the owner to make sure the reg doesn’t get contaminated with dirt, oils or greases.
The Z2 has two high-pressure ports, one each side of the main barrel.
The six low-pressure ports are arranged around what, at first glance, looks like a turret but is not. This could lead to problems with hose routes – except that a seventh lp port is located at the very end.
This means that the first stage is set up horizontally rather than vertically on the tank valve for best results, but you still need to give all your hose positions careful consideration. The optional turret version has only five lp ports.

Second Stage
The Atomic Z2 second stage lacks that wonderful universal joint that joins the T2X to its intermediate-pressure hose. It’s a feature that makes the regulator comfortable in the mouth because the hose never pulls, yet it doesn’t affect the breathing performance.
The Z2 has far more in common with all other regulators in this respect. However, it is pressure-balanced, and it has the Atomic high-pressure piston-seal system that keeps the valve seat and the “adjustable dynamic orifice” apart when the valve is not pressurised.
This allows you to store the regulator for months without it mysteriously leaking gas the next time you want to use it. The separation avoids engraving of the valve seat during storage. I have had an Atomic regulator for many years without a service, and whenever I get it out of my cupboard it performs perfectly.
Low-friction-bearing surfaces keep this action working smoothly, and a Kevlar-reinforced polymer insert at the pivot-point of the titanium valve lever is partly responsible. The body of the valve is made from brass plated with zirconium.
Where other regulators feature a venturi control adjustment or a by-pass tube, Atomic second stages have a unique depth-sensitive automatic adjustment that the manufacturer likes to call the “automatic flow control”. A vane simply swivels in the flow of air within the second stage according to the pressure applied to it by the water.
It also has an adjustment for the cracking effort needed to open the valve initially. I have always left this set at maximum, and I’m pleased to see that the manufacturer explains that tightening up this control actually adds to the work of breathing rather than saving air, as I have heard some people misinform other divers.

In the Water
Anyone who has jumped in and dislodged the exhaust valve of a regulator will appreciate that this can make it so wet to breathe from that it is virtually useless.
Atomic employs an elliptical exhaust valve, which it claims dramatically reduces the work
of breathing at depth. It is so substantial that there is no way it could be dislodged by a sudden inrush of water.
I missed the universal joint on the hose, but I still enjoyed the Atomic mouthpiece, which has to be one of the best ever made.
I asked Atomic to send me a few spares some years ago, and have fitted them to other makes of regulator I have used.
It’s proven that the apertures in the front of a second stage have a dramatic effect on
the regulator’s ability to perform to the highest level.
It is also my experience that when stationary in a strong head-on flow of water, as one might encounter watching animals at Manta Sandy in Raja Ampat, at Blue Corner, Palau or at one of the Express sites in the Maldives, a regulator can be affected and free-flow annoyingly.
Atomic has thought of this too. The holes in the front cover of the second stage are so designed that they direct any inward flow of water to the sides, and not directly on to the pressure-sensing diaphragm. It works.
Not only that, but the Z2’s front cover is flexible, so any part of it can be pressed to operate the purge control.
As with all Atomic regulators, it breathed sublimely. I couldn’t give it 10 stars because it’s not an Atomic T2X, but it is available to buy at an incredibly attainable price.

Sherwood SR-1, £378
Scubapro A700 MK25, £599
Apeks XTX200, £510
Atomic T2X, £1067

PRICE £355
FIRST STAGE Piston-type
PORTS 2hp, 7lp
VENTURI Automatic adjustment
COLOURS Grey or blue
CONTACT www.atomicaquatics.com
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