THE ANCIENT PHARAOH HAD A DREAM, and the Israelite Joseph interpreted it for him. His dream involved seven fat cows that were devoured by seven thin cows.
Joseph said that seven years of plenty would be followed by seven years of drought, and that the Egyptians should plan for that.
Well, that’s ancient history, but it does seem that many modern businesses experience cycles of success.
Mares, the Italian manufacturer of scuba gear, had its fat years, but more recently times seem to have been a little leaner.
This was not because it didn’t continue to make excellent products. It was linked to hiccups in its supply chain and the more aggressive marketing of its competitors.
The Mares Abyss Navy looks and feels exactly like some other current Mares Abyss regulators, except that this one has an all-black second stage – although I guess that members of special forces on covert operations would blank out the glittery Mares badge.
I’m told that this reg has been approved for use by the US Navy, hence its name.
When he was young and in the US Navy, my old friend Bret Gilliam spent a lot of time hanging about at great depths waiting to photograph the odd nuclear submarine as it stormed past him. I get the idea that something like that appearing out of the gloom at a particularly fast rate of knots is enough to raise anyone’s breathing rate, and he would have been very grateful for such an efficient bit of kit.
We have to thank the likes of Ian Himmens and Stan Ellis, who developed their erformance-measuring ANSTI machine since then, for the fact that there are few if any poor performers among scuba regulators now.
This Mares Abyss Navy certainly looks serious.

First Stage
This is a typical Mares balanced diaphragm-type design, with its two high-pressure ports angled steeply away, so that pressure gauges (or computer transmitters) are not fouled by any other hoses. The hoses are heavily marked for function. There are four medium-pressure ports, and these too are angled away from each other.
Characteristically, the port for the primary take-off to the second stage is of an over-sized gauge, allowing a wide-bore interstage hose to be used.
It’s quite a brute, with a great deal of metal surface area for good heat-exchange, and looks to be taller than other Mares first stages.
The diaphragm is oil-sealed by means of an extra part which is screwed onto the top of the valve to reveal the heavy-duty external pressure-sensing diaphragm. I wouldn’t give it to a child to play with, because I found the lugs let in to engage a servicing tool were on the sharp side, and could easily cut a finger softened by long immersion in the sea.
The intermediate-pressure hose is of traditional rubber design, for its superior heat-exchange properties and ruggedness.

Second stage
Black is the new black. Mares has abandoned the Flash Gordon retro-look it gave some Abyss second stages recently.
Apart from this, there are few surprises in the design of this part. It is very neat and compact, and has the familiar Abyss all-metal style, with only a small amount of plastic.
The front vent to the depth-sensing diaphragm is perforated with many small holes so that the effects of being head-on into a flow of water are mitigated, and free-flows avoided.
The purge button is clearly located in the centre of this, and presses on the valve lever for a progressive, effective flow when you need it.
There are no knobs for users to fiddle with in the water. None are needed, because it also has the familiar Mares-patented Bi-pass tube, which feeds gas directly from the second-stage valve to the mouthpiece, avoiding any fast flows across the inner side of the diaphragm.
These fast flows can lower the pressure at that point, causing the diaphragm to be pushed in further, and thereby opening the second-stage valve more and increasing the gas flow.
The result is exponential, making inevitable the sort of free-flow associated with freeze-ups in cold fresh water. The Bi-pass tube avoids this.
The main difference between this and other Abyss regulators is that all the metal parts have a fluoropolymer resin finish in matt black, and the small amount of plastic used is all matt black too. Even the hose protector, again perforated with holes to allow water to pass to the in-line heat exchanger, is finished in a matching matt black.
There is a single exhaust port, and the exhaust-T includes a protrusion that ensures that the exhaust port is kept in place. The exhaust-T is small but big enough to ensure that exhaled bubbles don’t become an annoyance.
As usual with Mares regulators, I felt that the mouthpiece was a little soft and flimsy when used in warm weather.
However, it hardens up to be quite adequate in a cold inland site, and it is use in cold water for which this regulator is intended.

In The Water
It’s getting more and more difficult to differentiate between the performances of top-of-the-range regulators. Mares claims just less than 1 joule/litre for the total work of breathing, and this is twice the figure claimed for some other regulators.
This said, neither figure represents much effort at all, when you consider that not long ago manufacturers were trying to beat the 3 joule/litre barrier, and high gas-flows represent a likelihood of exponential free-flows in the cold.
So although in side-by-side comparisons the Abyss Navy might seem harder to breathe from, this doesn’t amount to a hill of beans, as I’m sure those guys in the US Navy might have said. It’s just nice to know that it isn’t going to turn into an uncontrollable gas geyser in cold conditions.

I couldn’t get into the second stage easily to look at the lever action on the pressure-sensing diaphragm on the opening of the valve. Mares discourages anyone but a service technician from taking it apart by marking the fixing screw with a blob of red paint.
Too often, regulators can be reassembled incorrectly by the unskilled, leading to ingress of water and a wet breathe.
This robust, all-black, all-metal regulator looks the business and meeting US Navy performance criteria is no mean feat. I don’t know if it’s a psychological effect of the black finish, but it looks a lot meatier than some other superficially similar Mares regulators.
The excellent hose routeing of the first stage, especially favourable for divers using more than one cylinder, combined with the oil-sealed effect of the coldwater kit and the tried-and-tested Bi-pass tube of the second stage, are bound to appeal to extreme divers. Metal makes for good heat-sink characteristics.
The all-black finish will make divers look well hard, too! Perhaps this will signal the start of a new era for Mares.

Scubapro A700 MK17, £500
Apeks XTX200, £490
Cressi Ellipse Balanced MC9 SC, £306
Sherwood SR1, £378

PRICE £500
FIRST STAGE Environmentally oil-sealed diaphragm design
PORTS 2 hp and 4 mp, including one dedicated to the primary interstage hose
SECOND STAGE Mares Bi-pass tube
DRY WEIGHT 1125g (DIN version)
DIVER GUIDE width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100% width=100%