Question What mix to use for 200ft (60m)

[Eric Sedletzky]

I don't dive air below 45 m anymore but I can tell you that memory loss is not a something I've ever experienced. The conditions in the Med are very good in summer with clear and warm water trimix didn't really show before the early or mid 2000s and never really was widely available.
I wouldn't advice anyone to do it, especially not newer diver, but the not nearly as bad as people on the internet make it sound. I think most people don't know what they're talking about and are just repeating stuff they've been told. The whole thing about max air depth of 100 feet is pretty ridiculous.

Some people only use 32% down to 100’ and mix after that.
Air is verboten.

 

[tursiops]

I don't dive air below 45 m anymore but I can tell you that memory loss is not a something I've ever experienced. The conditions in the Med are very good in summer with clear and warm water trimix didn't really show before the early or mid 2000s and never really was widely available.
I wouldn't advice anyone to do it, especially not newer diver, but the not nearly as bad as people on the internet make it sound. I think most people don't know what they're talking about and are just repeating stuff they've been told. The whole thing about max air depth of 100 feet is pretty ridiculous.

You may be confusing two different things. The 100ft-max-on-air crowd may be a bit worried about narcosis, but are also quite concerned about gas density, so want to lessen it with some He ieplacing some N.

My experience differs from yours. I definitely begin to forget aspects of any air dive past 140 ft or so, by 150-160 ft I'm having a great dive but remember little, and by 185 ft I remember nothing of my air dives. This is all in warm, clear, low-effort water. I've done the exact same dive to 185-195 on air (once, thank you) and on Trimix (20/25 and 20/36); I have almost no memory of the air dive, and remember lots of details about the mix dives. I presume that my cognitive skills were greatly impaired on the air dive, but really don't know.

 

[Jared0425]

What is wrong doing these few dives on air? This is done commonly here in Europe...

In all seriousness, @tmassey is spot on. OC trimix for a half a dozen dives a year is reasonable. The deepest popular wreck on Lake Huron is either the Franz or the Florida at 230' which is comfortable at 18/45 which is about $300 for lp 105s. Anything above 200, 18/40.

 

[Angelo Farina]

Europeans aren’t subject to narcosis?

After our long training with alcohol, narcosis is nothing...

 

[Angelo Farina]

You may be confusing two different things. The 100ft-max-on-air crowd may be a bit worried about narcosis, but are also quite concerned about gas density, so want to lessen it with some He ieplacing some N.

My experience differs from yours. I definitely begin to forget aspects of any air dive past 140 ft or so, by 150-160 ft I'm having a great dive but remembers little, and by 185 ft I remember nothing of my air dives. This is all in warm, clear, low-effort water. I've done the exact same dive to 185-195 on air (once, thank you) and on Trimix (20/25 and 20/36); I have almost no memory of the air dive, and remember lots of details about the mix dives. I presume that my cognitive skills were greatly impaired on the air dive, but really don't know.

Here personal experiences may differ greatly. I have precise and fond memories of my juvenile dives below 50m. They were no more than fifty, and I remember each of them distinticly. Short and intense...
And dangerous, of course, which was part of the excitement. As said, juvenile experiences...

 

[Tracy]

In all seriousness, @tmassey is spot on. OC trimix for a half a dozen dives a year is reasonable. The deepest popular wreck on Lake Huron is either the Franz or the Florida at 230' which is comfortable at 18/45 which is about $300 for lp 105s. Anything above 200, 18/40.

Closer to $500 than $300.

 

[astr0b0y]

Closer to $500 than $300.

How much are you paying for He? In Australia we’re charged between 10 and 14c (AUD) a litre.

 

[Tracy]

How much are you paying for He? In Australia we’re charged between 10 and 14c (AUD) a litre.

I charge $3.50 per cf. I am currently the cheapest in the state.

 

[astr0b0y]

I charge $3.50 per cf. I am currently the cheapest in the state.

Thanks, that’s good info. I’ll stop whinging about the price here! We seem to be getting a good deal on He here.

 

[Tracy]

Thanks, that’s good info. I’ll stop whinging about the price here! We seem to be getting a good deal on He here.

It varies a lot across the country. I think in Florida you can get it for less than $2/cf and it is $17.50/cf at a shop in Wisconsin.