If trimix allows divers to go to 330 feet, what gas/mixture is used to go to 400 feet?

[ajduplessis]

Scuba diving is a non-competitive sport where many of the participants mostly care about "competitive" goals such as depth, time, SAC and perceived experience/skills as a measuring gauge to compare themselves to peers. You see these things in many threads and questions everywhere.

Unfortunately it seems that our DNA is wired to be competitive and this sometimes causes injury or death while scuba diving. Pushing the limits and trust me dives are prime examples where divers feel the need to be better or equal what those around them do.

 

[IDS_Bill]

Scuba diving is a non-competitive sport where many of the participants mostly care about "competitive" goals such as depth, time, SAC and perceived experience/skills as a measuring gauge to compare themselves to peers. You see these things in many threads and questions everywhere.

Unfortunately it seems that our DNA is wired to be competitive and this sometimes causes injury or death while scuba diving. Pushing the limits and trust me dives are prime examples where divers feel the need to be better or equal what those around them do.

So true - so true!

 

[HLIDD]

I don't think it will hurt to answer the question. I don't get the feeling it is to facilitate a dive to 400fsw... If you assume a 130ft END (equivalent to diving air at 130ft) and a PPO2 of 1.4, You're looking at 11/62 (ish). 11% Oxygen and 62% Helium.

There are some good apps that you can download so this is hardly top secret information.

That said, to do this type of dives, one needs the training and - especially - the experience. There are no shortcuts and you can kill yourself if you don't respect the procedures, planning, training, depth and everything else related to Technical Diving. So get wet, work your way up the chain and take your time - and enjoy yourself. But remember, Technical Diving is not a competition sport. It's not about the numbers but more about the dives themselves and what you will experience.

What are some apps to calculate this

 

[InWay2Deep]

What are some apps to calculate this

Pencil and Paper is the best place to start so you understand the math, but Gas Blender Toolkit is what I use.

 

[HLIDD]

Thanks

 

[SelfDiver]

What are some apps to calculate this

Oxygen percentage is calculated from your maximum desired Partial pressure of Oxygen (PPO2)
Let's assume you want 1.4 Atmospheres (ATA) of Oxygen
At 400 feet(122 meters) the breathing gas is at 13.2 ATA and 1.4/13.2 = 0.1061 and we will round down to 10%
The Nitrogen content comes from 40 meters diving with air 0.79*5=3.95ATA PPN2
3.95/13.2 = 0.299 rounded down to 29%
People call this Equivalent Narcotic Depth(END) or Equivalent Air Depth(EAD)

10% Oxygen +29% Nitrogen means that 61% is left for Helium
This is called TMx10/61 or Trimix 10/61 because the Nitrogen percentage is implied from the other two gases

You can hop over to the rebreather forum for discussion of setpoints and diluent. The rebreather creates a mix "on the fly" where instead of taking a cylinder (Tank) with a specific mix, you are constantly changing mixes as the depth changes.

Don't trust advise from strangers on the internet.
How is your frog kick? Back kick? helicopter turns?
Dives to 120 meters are no joke, but you can get there if that is your goal, even with PADI
It is great to have goals and I hope to see you in a technical diving course when you are ready for it
Open water
Advanced open water with deep and Nitrox specialties
Rescue diver + O2 + CPR/first aid
Tec basics
Tec 40
Tec 45
Tec 50
Tec 65
Tec Trimix (This course culminates in a 75-90 meter dive and you can proceed to dive deeper as you get more experience)

Enjoy the journey

 

[HLIDD]

Oxygen percentage is calculated from your maximum desired Partial pressure of Oxygen (PPO2)
Let's assume you want 1.4 Atmospheres (ATA) of Oxygen
At 400 feet(122 meters) the breathing gas is at 13.2 ATA and 1.4/13.2 = 0.1061 and we will round down to 10%
The Nitrogen content comes from 40 meters diving with air 0.79*5=3.95ATA PPN2
3.95/13.2 = 0.299 rounded down to 29%
People call this Equivalent Narcotic Depth(END) or Equivalent Air Depth(EAD)

10% Oxygen +29% Nitrogen means that 61% is left for Helium
This is called TMx10/61 or Trimix 10/61 because the Nitrogen percentage is implied from the other two gases

You can hop over to the rebreather forum for discussion of setpoints and diluent. The rebreather creates a mix "on the fly" where instead of taking a cylinder (Tank) with a specific mix, you are constantly changing mixes as the depth changes.

Don't trust advise from strangers on the internet.
How is your frog kick? Back kick? helicopter turns?
Dives to 120 meters are no joke, but you can get there if that is your goal, even with PADI
It is great to have goals and I hope to see you in a technical diving course when you are ready for it
Open water
Advanced open water with deep and Nitrox specialties
Rescue diver + O2 + CPR/first aid
Tec basics
Tec 40
Tec 45
Tec 50
Tec 65
Tec Trimix (This course culminates in a 75-90 meter dive and you can proceed to dive deeper as you get more experience)

Enjoy the journey

For me my goal is when i tern 18 next jan im going to do instructor and deco procedures then hopefully starting my rebreather corse. ( the reason i wanted how to find out about the gas mix is I’m doing an essay at school on trimix) p.s frog kicks is the hardest skill in the side mount course

 

[SelfDiver]

For me my goal is when i tern 18 next jan im going to do instructor and deco procedures then hopefully starting my rebreather corse. ( the reason i wanted how to find out about the gas mix is I’m doing an essay at school on trimix) p.s frog kicks is the hardest skill in the side mount course

Get good at frog kick, back kick and helicopter turns.
Can
We get a copy of your essay? I would be glad to help you with citations and references for trimix calculations. I graduated in the top half of my 8th grade class.
Consider getting a commercial ticket.
Why are you doing an instructor course? You can do rebreather and deep technical without the instructor rating.

 

[NothingClever]

…when i tern 18 next jan im going to do instructor and deco procedures then hopefully starting my rebreather corse.

Skip the instructor nonsense. That’s NOT the only path to proficiency as some people and certifying organizations want you to believe. Go from Adv OW to an introductory technical course. You’ll save buckets of money that you can direct towards your own diving, gas fills and higher training.