New to diving only a few in but 80% of my diving will be in very very cold water. IE ice diving/ glacier run off! Looking for cold water gear Poseidon keeps coming up as the best option. Is this just marketing or are they really worth the price? Right now looking at the full face mask.
"Is Poseidon Worth it?"
As of this year, I have been using their gear for forty-five years, and never once saw a reason to ever switch anything out, having had ample opportunities to use any number of other brands over the years. The regulators are almost "overbuilt" -- and the Swedes, to their credit, know a little something about cold water . . .
In answer to your question, you're thinking of the "Poseidon Atmosphere," which I have used for years -- both for the cold and for "suspect" waters while collecting samples. It is near-impossible to flood and it delivers air without fault, under both ice and "balmier" conditions, such as Nanaimo (British Columbia) Winter waters of 5˚ C and elsewhere.
There are a number of threads which mention the Atmosphere as well as the larger topic of full face masks, which are a real subject of its own; and may be an acquired taste, for some, as well as require some specialized training.
Equalizing may take some getting accustomed to, since the mask has a "nose-block" instead of having your nose easily available for Valsalva. The mask is pressed against your face and you blow through your nose against the adjustable block to equalize. Also, there is a potential danger of having to remove a FFM under very cold water conditions (the topic of bradycardia is mentioned, at some length, in a number of SB posts).
The Poseidon mask is fitted with an altered Jetstream (the so-called PP, swapped with the similar guts of an XStream second stage) and is positively-pressurized; that is, it is intended to slightly free-flow into the mask, which serves to offer a positive seal; to continually defog the thing, and to further vent any potential CO2 build-up. It is usually mated to an XStream first stage (which is great under the ice, right out of the box, and requires no further environmental futzing), though I initially used them with the 2900s (the Odin, in the US), years back, along with either a metal or rubber environmental cap, filled with either vodka or a tasty alcohol and glycerin combo.
The Atmosphere will also require a hood, intended for FFM diving, with a neoprene skin, for the FFM to seat, since it doesn’t seal well against typical wetsuit nylon; and it cannot be worn under a hood, due to the positive pressure and potential buoyancy issues that would created. It can also easily be fitted with communication devices, if so desired.
Ballasts may also be required, for shallower waters, in the form of weights (see photos) that can be mounted to the mask itself, on its "rail,” which are now on the expensive side, but can easily be cobbled together, as we did, for years, from rubber bicycle tubing; lead shot and cable ties . . .
