Mix Gas Sidemount Scuba Diving

Nitrox or Helium, either way, in sidemount!

For a while now, Nitrox (oxygen enriched mix) and or helium based mixes, aka trimix, have been the sole toys of technical divers. It is true in a way, and thanks God to these different mixes, man (ok, women as well!) are pushing the limits of scuba diving and helping understand the intricacies of deep, very deep diving as well as decompression models. If Nitrox is not new, nor is helium, they are still seen as ‘voodoo’ mixes.


A Nitrox diver certification allows for great bottom time (no pun intended!) , less nitrogen intake and shorter surface intervals between subsequent dives. That is great stuff, so great that one agency in particular, only has its divers use Nitrox 32 (enriched air with 32% of O2 content). But there is a downside to this: oxygen is as narcotic if not more narcotic than nitrogen, the other gas that impair our judgment, pass 30 msw. We need oxygen, but a too high content of it will lead to what we call, oxygen poisoning or toxicity. This is simply due to breathing an oxygen rich content at depth. What happens is that our body can only tolerate a certain partial pressure of oxygen. What is partial pressure of oxygen (PpO2), would you ask?
To put it simply when we talk about PpO2, it’s as if we were breathing only oxygen or if O2 was acting alone in our breathing mixtures. A too high PpO2 becomes a problem to us, divers. These studies come mainly from the medical hyperbaric  medicine.
So to reduce this O2 content technical divers use Normoxic or Hypoxic mixes. One is breathable at the surface and the other one is not enough rich in O2 to be breathed at the surface and implies travel gases.

Now that you understand, a bit better (I hope) the concept of Voodoo mixes, let’s bring this thread back to recreational diving!
For the Nitrox and Deep diver, the next step in line, after having successfully passed the Sidemount Open Water program, would be to join either an Advanced Nitrox or Advanced Recreational Trimix course (ART).

IANTD Courses flowchart

If I had to choose, I’d go for the ART course directly. As it offers ‘clear head’ deep diving (max 48msw) and it makes of a great transition to Technical diving and expose divers to rigorous dive planning and protocols that will be used during their next course (i.e Normoxic trimix).

Now add this with diving on the Razor Sidemount System and you got yourself the sexiest dive rig since the creation of the Inspiration Classic Rebreather! (reference to an ad for AP in dive magazine – I do not own or intend to own an Inspo) So join us on our next ART sidemount course and explore the fun of mix gas diving and the freedom of sidemount scuba diving!

Picture from Sidemounscubadiving.com

After getting your scuba gear sorted, it will be time to hit the water and get those scuba skills sharpen and ready for some Voodoo scuba diving!

About Jason

Essential Scuba Training is aimed at divers looking to better their skills in recreational and technical diving while using a holistic configuration. Be it recreational or technical and/or cave diving, Essential Scuba Training will put it's twenty years of experience at your service. View all posts by Jason

3 responses to “Mix Gas Sidemount Scuba Diving

  • Ron Goodman

    Hey Jason, I missed seeing you when I was in Playa last week. I did Normoxic Trimix and the single stage cave course with Nando. I really like the new Razor and wing. Next summer will probably just be a Tech Cave upgrade and a lot more cave diving. See you then, be safe.

    • Jason

      Hey Ron,
      I was busy most of the time you were here. Just have couple of days off now after Cavern Diver training and a group of Cenote Divers!! Fun with the rain as well!! :))
      Looking forward to diving with you next time you come over. Take care my friend.
      Cheers
      Jason

  • Greg

    To those divers that are curious about Jason..I met him on a Cenotes dive 2009.He introduced me to the Cenotes. I felt safe & secure with him diving.I came back again this yr and did more diving with him in new Cenotes locally.Your safety is always a #1 with him.He gives you alot for the time and $.,as well as helpful instruction.He is a asset to the diving community in the Mayan area.He has become a a trusted friend & diving companion.
    Great helpful points above,with a spoonful of humor..
    Tres Bon ,Jason

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