Advantages of Trimix?

[down4fun]

Heart a lot about Trimix lately. I'm always interested in learning new things about diving. Can somebody explain me what are the advantages of diving with Trimix?

Air is 21% oxygen and the rest Nitrogen (some tiny percentages of other stuff but for this conversation o2 and N2). In recreational depths N2 becomes a limiting factor to your NDL's So the next step then is to reduce the nitrogen, this can be done in shallower depths by adding more O2, hence nitrox. Increase the O2 decrease the N2. But as you go deeper O2 itself becomes toxic. Also N2 is responsible for narcosis, so now you have to decrease the N2 for narcosis and the O2 for toxicity. Helium has become the norm for this third ingredient. It is an inert gas, meaning it doesn't it isn't metabolized or used by the body making it the best answer (so far). Helium is absorbed into you tissues faster than the other gases and so slowly ascending and being able to hold stops in order to off gas the helium at the correct rate is very important.

Most people have no idea how narc'd they are doing regular recreational dives, especially beyond 100 feet. As an AOW diver using nitrox on the deeper dives there would be parts of the dive I didn't remember until some one described it. That was narcosis. I have done some of those same dives now on trimix and remember every minute of the dive, the features of the wreck, and am more aware of my buddies and environment.

But all good things come with a cost and for helium it's just that...the expense. At our local fill station you can get nitrox for .10/ft and trimix is .35/ft. So you can see that trimix is significantly more expensive. But for anything past recreational depths it is absolutely necessary. If you can't afford the gas, the right gas,then you shouldn't do the dive.

Hope that helps

 

[Rhone Man]

Heart a lot about Trimix lately. I'm always interested in learning new things about diving. Can somebody explain me what are the advantages of diving with Trimix?

It stops your wallet from getting too heavy.

 

[ScubaBB]

It sure helps.

 

[MXGratefulDiver]

Instead of paying $7 to $10 for a nitrox fill, the 21-35 can run between $15 and $25, depending on your relationship witht he dive shop, and what kind of deals they have put together for helium deliveries, and how good they are at re-using with Haskels , etc.

When you consider the time out on the boat ( time costs you, in a real sense), the cost of the boat trip, the value of the intense experience you want to have, and the safety value( value of your life) , I don't think the helium cost is all that high

You pay less for helium than I do ... back when I dived doubles, a 21/35 fill in my HP119's would run me about $60 ...

... Bob (Grateful Diver)

 

[MXGratefulDiver]

The last option sounds good. And I do have the possibility every once in a while. But isn't it very dangerous to breath Trimix on 35 meters, without having done a proper course yet.

Not if you use it in the manner I described. The potential danger with helium is that it is a very light substance which ongasses and offgasses very quickly. If you're using it for your dive, you should take that into account for your ascent rate ... it's much easier to bend yourself on helium than on air or nitrox. But for a minute worth of breathing at depth, it won't really change anything except your sensory perception ... in effect, you'll suddenly realize how narc'ed you were before switching to it. Switching back to your own gas, you will also be more aware of how narc'ed you become. Now you will have a better comprehension of how insidious narcosis is, and how narc'ed you've been at those depths without even realizing it.

... Bob (Grateful Diver)

 

[Bombay High]

I agree with you, I thought it would be more expensive. It probably is in Croatia.

Helium is probably cheapest in the US (or a bootlegger in Aberdeen or Dundee)

 

[Bombay High]

It is expensive enough that British Petroleum and Shell recycle it out of our exhaust on deep mix (closed circuit surface supply)

 

[Tortuga68]

As you go deeper the nitrogen produces narcosis or the "martini effect" like you learned about in OW. So the next step then is to reduce the nitrogen, this can be done in shallower depths by adding more O2, hence nitrox

O2 is more narcotic than N2

 

[ScubaBB]

@grateful diver

Gonna try it ASAP

 

[Rhone Man]

O2 is more narcotic than N2

Allegedly... but that is a looooonnnggg conversation.