Normoxic trimix (nitrix) for 100 foot dives

[boydski]

We do quite a bit of diving in the 100 - 130' range on light normoxic or hyperoxic trimix, but this is usually the result of topping off left over mix with continuous blend Nitrox. This works very well (I enjoy the crystal clear head at "recreational" depths) and keeps you from "wasting" all of that good helium in your tanks that are left over from a deep dive.

Having a couple of sets of doubles helps with the "juggling" that is sometimes required to make this work, and doing your own fills keeps the cost down.

 

[String]

All my prices are UK and the measurments metric but to give a general idea.

One place here sells helium for £0.02 ($0.04) per litre used. This is fairly common.

So for a fairly weak 30% heium mix that would cost around £17 ($30)for a 12l tank (nearest thing we have to 80 cuft). Then you add on the cost of the air to top that up and the O2 (if its a more compled mix). The result is you're looking at roughly £20 ($35.35) per tank for a weak normoxic helium mix.

Now add into the fact that if you're doing deeper diving you really want a twinset for that not a single tank so double that price.
Doing stops (even safety stops) on helium isnt great so you'll want a 7l or so tank with some 50% or higher O2 in. Add another £8

Total cost per dive around £50 ($88.37)

Total cost for same dive done on air/nitrox = £10 ($17.67)

Or to try to compare like with like.

A single 12l (roughly an 80 cuft) tank with air £3 ($5.30)
A single 12l tank with trimix £20 ($35.35)

That cost alone is the main reason deep-air is still common here for depths <50m (165ft). Air is far from ideal but for a lot of people its all they can afford. That or they'd have to skip 5 other dives to save up the cost of one trimix dive.

Edit:- to put a direct comparison on the 32/17 fill listed above for a 15l tank (near the same thing) you'd pay &#163;11.83 for the helium, &#163;2 for the oxygen and &#163;3 for air on top of that so &#163;16.83 for one tank ($29.74)

It certainly appears trimix is near twice the price here as the USA if thats correct.

 

[wb416]

just wondering. How much would it cost to fill a 80cft tank with a popular mix. I have never dove it. and i'm not certified to either.

here's an example of gas prices in S Florida.

YMMV

 

[MXGratefulDiver]

here's an example of gas prices in S Florida.

YMMV

LOL ... that is obviously a GUE shop ...

Air - $0.08 / cubic foot - Not Recommended for Diving

:browsmile

... Bob (Grateful Diver)

 

[wb416]

LOL ... that is obviously a GUE shop ...

Air - $0.08 / cubic foot - Not Recommended for Diving

:browsmile

... Bob (Grateful Diver)

It's one example of pricing.... stay focused bob... ya didn't have to say the "G" word...

 

[daniel f aleman]

South East Florida DIR

South East Florida DIR is a group for DIR Divers of all levels, dedicated to the DIR lifestyle. We frequently post dives, practice sessions and discuss topics related to the DIR Diving Style. Please feel free to join our group to meet other DIR Divers in the area.

Big-time G shop, great mixes, though.

 

[brianstclair]

Couldn't help but notice that one too, though. "Not recommended for diving"?? C'mon.

Brian

 

[String]

Here are some uk trimix prices:

http://www.divedorset.com/airandgasprices.htm
http://www.ndac.co.uk/gas_prices.htm

Multiply prices by 1.76 to get price in us dollars

 

[matt_unique]

here's an example of gas prices in S Florida.

YMMV

Ditto NW - the reference to air in that table is awesome....

I wonder if there is a website that refers to "DIR - not recommended for diving"

--Matt

 

[TSandM]

Yeah, it's a New Jersey wreck diver's site . . .