Not diving to greater than 30m/100ft unless with helium

[ScubaInChicago]

It's about $12-15 for 2-3 hr dive @ 250-300'.

 

[rx7diver]

It's about $12-15 for 2-3 hr dive @ 250-300'.

Yeah, but you guys also have to pay for scrubber and oxygen sensors and amortize (is this the correct word?) the cost of a $1M SCR or CCR + training. IJS.

 

[DevonDiver]

If helium cost on a par with oxygen, we could all be using it as we would nitrox. Normoxic trimix would be the optimal gas for deep recreational dives.

But helium doesn't cost like oxygen, especially outside the USA. Neither is it as commonly available in many locations around the globe.

Therefore, the decision to use helium becomes a very personal one. That decision is based on many factors, not least the issue of safety-cost-benefit.

 

[Nuribromanski]

Normoxic trimix would be the optimal gas for deep recreational dives.

can u compare NDLs 4 he blend ur talking about w/ ndls 4 air? bc not sure trimix would be optimal 4 any deep dive w/o deco...saturates fast tissue 2 fast

 

[ScubaInChicago]

Studies have shown although he on gasses faster, it also offers gasses quicker. I know quite a few divers who don't even tell the algorithm there's any helium to avoid being penalized for it. I would however recommend controlling your ascent rate when using helium. CESA is not your friend at depth.

 

[tomfcrist]

Normoxic trimix would be the optimal gas for deep recreational dives.

can u compare NDLs 4 he blend ur talking about w/ ndls 4 air? bc not sure trimix would be optimal 4 any deep dive w/o deco...saturates fast tissue 2 fast

The simple answer is that adding He to the mix will always give you less no-deco time than without He.

 

[GrimSleeper]

This research is in its early stages, but suggests that all the old assumptions about NDLs, deco times etc with Helium are wrong...

https://digital.library.adelaide.edu.au/dspace/handle/2440/92699


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[ScubaInChicago]

Yeah, but you guys also have to pay for scrubber and oxygen sensors and amortize (is this the correct word?) the cost of a $1M SCR or CCR + training. IJS.

Sorb is about $10 for up to 3 hours of smaller dives or 8-10 hours on a big dive. O2 sensors are $100 ever 4 months. To put it in perspective, the last trip I did saved more than half the cost of my unit in gas savings.

---------- Post added October 7th, 2015 at 08:18 PM ----------

What I came away with from a presentation by Doolette was that the gas model is as reported in his findings, but... it doesn't mean the added time is not in fact needed. Adding some conservatism doesn't hurt vs. riding the knives edge of deco obligations by omitting he from the algorithm.

 

[Centrals]

I believe in the benefits of helium enough that I routinely use 15/55 on 100' dives and shallower without a second thought.

The last time that I used an hypoxic mix was on HMS Prince of Wales(66m) and the 50% deco mix was used as travel mix as well.

In Philippines I paid US $0.07 per litre for helium. So a twin set of 11L(15/55) will set me back ~US$170.00.
There are not that many CCR friendly operators within The Coral Triangle. And if you want to include He then the number is even smaller.
I wonder how many operators in Komodo, Maldives, Raja Ampat, Sipadan and Tubattaha offer CCR and He?

 

[JohnnyC]

So the psychological aspects of these divergences from plan might have been more significant than any physiological impacts, for hér ?? maybe???

I think it would be a more accurate estimation to say the psychological aspects would have compounded any physiological impacts.

I think this is true of anybody when their dive deviates from their dive plan to the point that it becomes psychologically impactful. It can be true for any number of situations. To what extent is of a personal nature.