Jetsam SNOG Valve Teardown

Jetsam SNOG Valve Teardown
By Ben Field

Most people will, I'm sure, be aware of the Jetsam BOV. Maybe even from its early Sherwood regulator days but more likely the second generation model with the infamous Paragon and most recently the Mares Proton 2nd stage.

An anomalous step in this evolution was the SNOG valve (Simplified Non-manipulated Oxygen Gate according to Gordon with a certain wit no doubt,) a direct fit replacement for the 2nd stage on the later DSV's that allowed hands free access to O2 and Dil.

This unique piece of rebreather equipment hasn't received a wide audience, to my knowledge, so I present it here in review/teardown form as a testament to Gordon and Jetsam's pioneering and inventive spirit.

Before I go any further I should point out that the SNOG is NOT available from Jetsam or anywhere else, mine was one of what I gather was a pre-production/prototype batch of limited number and was purchased second hand. Kim informs me Jetsam have no plans to sell the SNOG in the future.


Simply put the SNOG replaces the 2nd stage of the BOV with a tongue operated manual O2 and Dil add system, pushing the lever Right lets in Oxygen and Left Diluent. The lever cannot be activated accidentally as it sits outside your mouth just ahead of your front teeth.

The most important point is that the O2 and Dil are release directly into the DSV so could be inhaled directly with obvious effects in the case of O2 at depth! In practice this is difficult to do and the "exhale and tongue out" manoeuvre is quickly learnt. The gas release is also very progressive allowing you to add very small quantities of gas as required and as the release is so close to your head you can hear and feel very easily the speed and amount of addition giving very fine control.


Additionally the paddle on the front (marked Dil and O2) can be pushed by hand to allow gas to flow like a purge button, however it is far less controllable than with the lever.


The lever pivots on two stubs positioned to allow only the horizontal movement, springing action is provided my the O2 and Dil feed valves and the rubber gasket that doubles as the waterproof seal.


The valves operate on the same principle as the simple KISS ADV, deflection of the stem unseats a small o-ring releasing gas, this time the arrangement is much smaller.


(Please excuse the dirty carpet!)
Here you can see the breakdown the valves themselves, I have assumed these are stock parts from somewhere (Swagelock perhaps?) The stem and o-ring (not shown) are very small; I strip these down periodically for a clean as they are prone to getting abit of water on them when the unit is riding to and from the dive site, while it can still be switched to close off the loop, the SNOG leaves the has its interior exposed at all times.


Once assembled you can see how the lever acts on either valve depending which way it is pushed. It can be used rather than the ADV on descent or instead of the MAV, I have not had much cause to assist the ADV but I now use it almost exclusively to add Oxygen.

I originally purchased the SNOG as a curio with no intention of using it beyond a single days testing, however I found it so pleasant to use, particularly when taking video or scootering that it has stayed on my unit all year on dives down to 50mtrs and with considerable workload and found it to be a superb addition.

You will note that I have had to give up the QR at the DSV end of the breathing hoses as the O2 and Dil hoses would not fit otherwise, however the benefit of the SNOG outweighs this inconvenience. I have also had to place a OC 2nd stage on a necklace to give full OC access again which is something of a step back, however a certain level of SCR and OC access is achievable with the SNOG as the Dil valve can supply suitable large quantities to breath from if you are willing to exhale through your nose. While not something I would want to do for long it does give the ability to go semi-OC almost entirely hands free.

Much like the KISS famous warning label reads "This device is capable of killing you without warning" the SNOG should be regarded with equal caution. Treated with respect it is a superb piece of equipment and I hope that in the future it might return in some form or other.


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