REGULATOR Mares Proton Ice

IT DOESNT OFTEN HAPPEN, BUT WHEN IT DOES, I GO PREPARED. What Me, diving in cold fresh water It can be as cold in the water at Stoney Cove in winter as almost anywhere in the world. So whats my choice of regulator under these dire conditions For a February trip to this Midland Mecca for divers, I took a Mares Proton Ice with a coldwater kit fitted.
     I hadnt left the shore before the regulator on the other side of my tank H-valve started playing up, gushing and roaring like a burst pipe. I wont mention the brand. The Proton Ice, however, behaved impeccably.
     So why did I choose that regulator and that model The Proton Ice comes with the V32 first stage, which is a direct descendent of the MR22 supplied with the Mares Abyss and the Mares Ruby. It has merely been pared of excess metal and hence weight.
     It has six ports, four medium-pressure and one over-sized to accommodate the wide-bore hose of the second stage. The high-pressure ports are sensibly angled away from the route of the other ports so that hp transmitters and hp hoses are not squeezed by others.
     It has Mares patented Dynamic Flow Control, which minimises pressure drop and with it temperature drop during the inhalation phase of breathing. The valve also has a spherical core seal system which avoids abnormal wear.
     Ever concerned that I have the best experience, Justin from distributor Blandford Sub-Aqua kindly fitted an optional coldwater kit, too. This ensures that the works of the diaphragm regulator stay dry and the diaphragm itself stays lubricated and flexible, reducing the chance of malfunction because of icing.
     The Proton Ice second stage is made of metal, including the mesh grid at the front, but is otherwise similar to the standard Proton. The even newer Proton Metal has a traditional shiny finish rather than the rather avant garde frosted look of the top-of-the-range coldwater model.
     I imagine there will be some hairy-arsed members of the diving public who would rather be seen dead than using a regulator finished in pale blue and misted metal!
     So whats special about metal Divers started having trouble with free-flows in freezing conditions only once regulators had been developed to provide todays massive flow-rates, and makers advanced to lightweight plastic construction.
     The coldest water is usually warmer than 0ÂC (its very hard to swim in ice). But the air supplied by your regulator can be very cold indeed, because thats what happens when a gas is depressurised, just as your tank gets hot when its pumped.
     Start off your air supply at, say, 4ÂC, a temperature common in freshwater sites in winter, and it can become very cold as the pressure drops from more than 200 to 8-15 bar at the first stage, depending on your depth.
     Any water in or around the first stage could turn to ice crystals, which can jam the mechanism.
     There is another temperature drop at the second stage, and this very cold air can be warmed up only by the water surrounding it. Metal conducts heat better than plastic, and although there may not be much heat in the water but there is a lot more than there is in the air passing through the regulator.
     The metal parts of the regulator serve to conduct this heat to warm up the air. The Proton Ice has heat-exchangers on the hose, too, but I think this is more to ape the fashion of other manufacturers who add heat-exchangers where their second stages are made of non-heat-conductive thermoplastic.
     Mares goes further by directing the main supply of air away from the works of the second stage by means of the venturi bypass tube or VAD (Vortex Assisted Design).
     I have found this design very effective in avoiding exponential free-flows, and the designers at Mares dont think it necessary to furnish their regulators with venturi  switches or breathing-resistance adjustment knobs. You just stick them in your mouth and breathe. All the clever stuff was done when it made the regulators.
     I did everything wrong when I tried the Proton Ice. I left my tank in my car overnight so that it was well-chilled. I took some heavy breaths from it while standing at the shore before diving - a surefire way to introduce ice into the main body of the second stage and affect the demand-valve mechanism. It didnt.
     I cannot guarantee that a Mares Proton Ice will not freeze up on you, given even more extreme circumstances, but if you buy one and it happens, please let me know.
The Mares Proton Ice (£385) with optional Coldwater kit costs £435.

  • Blandford Sub-Aqua 01923 801572, www.blandfordsubaqua.co.uk

  • Divernet Divernet
    + Has all the features of a regulator for use in cold water

    - None come to mind