MARES HAS NOT HELD BACK in submitting budget kit for test recently, and in doing so shows commendable confidence in even its entry-level ranges.
When it comes to regulators Mares, founded in 1949, draws on long experience. In the 1970s it collaborated with US manufacturer Voit, which developed the patented VAD venturi system used in Mares second stages. It later absorbed Dacor, another US scuba giant responsible for some striking regulator breakthroughs.
Having been highly impressed by Mares’ most expensive model, the 82X first stage paired with the Epic Adj second stage, I was keen to try out the less expensive 72X combined with the unconventional under-arm Loop.
Mares has mostly committed to balanced-diaphragm operated first stages, believing they offer higher performance than balanced-piston models, something makers of piston regulators will no doubt contest.
The 72X has one high-pressure port for pressure gauges or transmitters on each side. It then has no fewer than eight mp outlets.
Most recreational divers will need four at most – one for their primary second stage, another for an octopus and possibly two more to run BC and drysuit direct feeds. The idea of having so many mp ports is simply to provide plenty of choice for configuring your hose routeing.
Four face straight down when the first stage is “upright”, while the rest lead off from the sides.
Vertical lp ports.
Mares says that each port provides very high flow-rates, allowing a lot of gas to be supplied to more than one hose simultaneously.
Simultaneous demand for such high flow to multiple ports could occur during emergency sharing with another diver using your safe second, especially if you’re trying to inflate your BC at the same time.
Regulator designers commonly use a dedicated port to serve the primary second stage, to ensure that it gets the lion’s share of air when demand is high, because some first stages couldn’t supply equally large volumes of gas to all the ports in unison.
In such cases, priority is given to supplying the port from which you’re breathing.
A downside to a priority port is that it limits options for configuring your hoses. This has become more of a problem with the emerging popularity of technical diving, including sidemount. By providing so many choices of high-flow mp ports, the 72X is meant to eliminate compromises in laying out your whips.
It also facilitates a progression from rec to tech without buying a new first stage.
Mares uses a system it calls DFC (Dynamic Flow Control) to boost gas flow through the ports. This harnesses the venturi effect, with air routed to cause a vacuum that pulls other air after it. Reducing pressure drops in the first stage as you inhale is meant to make breathing easier.
The 72X is 40% nitrox-compatible out of the box. It is CE-rated for diving down to 4°C, though CE testing imposes fairly short periods for this freeze test. For colder conditions and longer dives, a choice of two isolating caps can be fitted over the main spring, which is otherwise open to the water.
It is possible, especially if ice-diving, for icing to occur here and block the operation of the spring. One coldwater kit surrounds the spring with silicone, which resists freezing; the other uses air, an excellent insulator.
The 72X is available in yoke or 300-bar DIN fitting. I prefer DIN – along with allowing use of high-pressure cylinders, it’s much harder for the captive O-ring to blow or for the first stage to be dislodged by impact.
DIN fittings can be difficult to remove from a tank with wet hands, but the Mares handwheel solves this. The 72X tank connection is protected by Mares Auto Sealing Technology, which closes off the inlet when it’s not pressurised. If you drop the 72X into a dip tank without its dust-cap, it shouldn’t leak water into the mechanism.
There’s a small wreck off Gibraltar that has an engine-room ideal for underwater photography. The light streams in from overhead and falls on the motor blocks and rungs of a crew-ladder.
Just behind is a small cabin, entered through a narrow doorway and, in its ceiling, a tight hatchway leads back into open water.
Most of my regulator hoses are routed to avoid catching in confined spaces. I’m nowhere near as fastidious about this as tekkies like Mike Ward, but it works for me – except for the second-stage hose feeding me air.
This hose must be long enough to allow me to move my head from side to side comfortably and, by tradition as much as for any other reason, it comes over my shoulder. This creates a loop, and that loop seems to have a magnetic attraction for fouling.
In Gib, it tends to catch just as you put your head through the door-frame, so it’s caught up behind you, where you can’t see it. Now you’re stuck in a barge 15m down. That’s when it finally dawned on me to tuck the hose under my arm.
The Loop does away with over-the-shoulder routeing and leads the hose under your arm from the get-go. This isn’t new – I have a 50-year-old Australian SeeBee that does the same, and Sherwood has offered one since the early 1990s.
Under-arm hoses are used by AGA on its professional sets for SAR and police divers, too, but the concept has never really caught on among leisure-divers.
Perhaps the Loop seeks to solve a problem that doesn’t exist for many divers, but for those who do dive into tight gaps, such as in wrecks, it merits attention. It’s possible to run virtually any second stage under your arm by adding a swivel, but these can badly restrict air flow. The Loop is designed for the job.