deep air

[Gilldiver]

Of course there is a big difference between doing a dive at 150 feet as a tourist, just swimming around or being pulled by a scooter and doing a working dive where you need to pull out a tool bag and get something done.

Anyone wonder why it is that the guys that are talking about deep air diving, the methods and ability to do it are the ones who do work at depth and the ones who are saying you shouldn't/can't do it safely yada, yada, yada are the ones who are the tourist?

Some can do the dive, some can do the work, few can do the dive and the work, and most of them can do it on air or mix.

 

[Rainer]

An inanely one-sided view of things.

Many of these 150' commercial dives are also tethered, require no real/complex navigational decision, no penetrations, no line running, no artistic video/stills, no deco obligation to calculate (if someone upstairs is controlling it), no mid-water work (if you're just being hauled back up), no team to track, no scootering, have comms, surface support, a decompression chamber above if things go south, and the job, not enjoyment is the main issue.

To be blunt, I probably couldn't do the dives the commercial guys are doing (regardless of gas choice), but then again, they probably can't do the dives we're doing either (regardless of gas choice, but being narced out of your mind sure isn't going to help).

Of course there is a big difference between doing a dive at 150 feet as a tourist, just swimming around or being pulled by a scooter and doing a working dive where you need to pull out a tool bag and get something done.

Anyone wonder why it is that the guys that are talking about deep air diving, the methods and ability to do it are the ones who do work at depth and the ones who are saying you shouldn't/can't do it safely yada, yada, yada are the ones who are the tourist?

Some can do the dive, some can do the work, few can do the dive and the work, and most of them can do it on air or mix.

 

[Rainer]

If you have 3 hours of trimix and unlimited air and you have to do multiple dives to 300' and 200' for example, I'm using the trimix on the 300' dives and air on the others. You simply don't have the luxury of unlimited trimix everywhere on the planet.

You're using an example of a working dive, not a dive done for recreation. Has no bearing on me.

It's like a rich man wondering if he's wants to eat roast beef, steak or lobster without the knowledge that there are people who are saying "throw me a bone here." Not everyone can afford trimix gas, not everyone can afford trimix training and others don't think they need to dive trimix on every dive.

I started trimix diving as a graduate student, hardly wealthy. It's a prioritization issue. I want to have fun, safe dives that I actually remember. I PLAN to be doing lots of complex decision making at depth. That's just part of the fun. Diving stoned doesn't help. I'd rather *prioritize* doing fun dives, which means choosing gases to help *me* have a good time. If that means I can't dive in some far off places or deep every day, so be it. Locations with no access to helium are probably also the same ones with less readily available hyperbaric medical facilities to treat me if I did make a mistake, which of course is more likely if I'm diving stoned. In such remote locations, I'd rather just keep the diving shallow. In any case, to do deep dives safely, regardless of gas mix, you're going to need to spend some money. Really no way around that.

If we only want to retain maximum clarity, we should dive trimix deeper than 50' on every dive. When I have trimix available for free, I don't NEED trimix at 50'. It's a matter of what do you require to maintain an acceptable degree of safety at the depth projected.

I *love* have you just as arbitrarily come up with 50'. Why not 20'? Yes, we *do* need to decide (for ourselves, our families, and teammates) what level of cognitive impairment is acceptable. No question that just submerging in water is already reducing cognitive functions. The issue is how far are you willing to let those functions deteriorate. And they will with increasing depth. And the consequences of bad decision making ALSO magnify with increasing depth. That CESA you so love from 50' might not be a big deal, but if your poor decisions lead you to do the same from 150' with 30 minutes of deco, you're likely not to have such a positive outcome.

For me this depends upon the length of the dive and the job at hand. I'm happy to wield a welding torch at 200' on air for an hour; there are some who would cut their leg off at the surface.

You're again using an example of a working dive, not a dive done for recreation. Has no bearing on me.

Competence depends upon training and experience. We can't throw stones at another before we understand their competence level. The only comparison you can make is with yourself. Like I said, there's nothing the matter with your approach, for you.

No kidding to the first sentence. And who is throwing stones? I'm just disagreeing with your earlier suggestion that we should all go get deep air experience before diving trimix. I *do* think that's stupid. To me it's like suggesting all 16 year-olds first learn to drive drunk so that they could manage getting home from a late night out at the bar. It misses a more obvious solution.

Really, I get it that there are easy dives you can do on air at 150' (and deeper). There's nothing the matter with your approach, for you. But that's not how I dive.

 

[Thalassamania]

There are pretty complicated dives that get done, on air, from 150 to 190. No tether, lots of real time, complex navigational decisions, occasional short penetrations, almost always line running, lots of photography and complex instrument servicing, deco obligations are calculated before the dive not during, plenty of mid-water work, lots of critical team work, rare scootering, no comms, no surface support, no decompression chamber. Science and risk management, not enjoyment, are the only issues.

We have for over half a century relied on good training and lots of planning and practice.

 

[SurDo2]

An inanely one-sided view of things.

Many of these 150' commercial dives are also tethered, require no real/complex navigational decision, no penetrations, no line running, no artistic video/stills, no deco obligation to calculate (if someone upstairs is controlling it), no mid-water work (if you're just being hauled back up), no team to track, no scootering, have comms, surface support, a decompression chamber above if things go south, and the job, not enjoyment is the main issue.

To be blunt, I probably couldn't do the dives the commercial guys are doing (regardless of gas choice), but then again, they probably can't do the dives we're doing either (regardless of gas choice, but being narced out of your mind sure isn't going to help).

Yes, to be blunt you probably couldn't do most of the dives we're doing but most experienced commercial guys I know could easily jump right in to most technical diving environments without missing a beat.

 

[PfcAJ]

Yeah! Lots of people do it, so it must be fine, right? Its all just fine, till it isn't.

DCBC's post in the accidents and incident's forums is a real good example of how things are just peachy, then go downhill in a hurry. Slippery incident pit.

Why put a foot on the banana peel if you don't have to? Back in the 80s, we didn't know better. Now, we have the ability, and resources to reduce narcosis. There was also a time when there weren't seatbelts. Can you be safe without a seatbelt? Sure. Until you get into a wreck.

 

[Rainer]

And of course luck. I have no question that at 190', in an emergency that requires critical and potentially complex decision making, you're going to be a lot better off on trimix than air.

You can train and plan all you want to accomplish generally rote skills at almost any level of cognitive impairment. Thousands of people drive home absolutely hammered every single night. When little Susie happens to unexpectedly dart into the road is where problems arise.

In any case, again, I don't doubt that even relatively complex dives can be done on air at these depths. They just aren't going to be as much fun as doing the same dive with a nearly crystal clear head. Add to the dives you just described scootering (in low vis, *while* running line, *and* while videoing), while computing the deco (tracking average depth and run time), and you might decide helium is a nice addition. If not, that's cool, too. No one says we have to agree.

There are pretty complicated dives that get done, on air, from 150 to 190. No tether, lots of real time, complex navigational decisions, occasional short penetrations, almost always line running, lots of photography and complex instrument servicing, deco obligations are calculated before the dive not during, plenty of mid-water work, lots of critical team work, rare scootering, no comms, no surface support, no decompression chamber. Science and risk management, not enjoyment, are the only issues.

We have for over half a century relied on good training and lots of planning and practice.

 

[Rainer]

I'd love to see some of your deep cave and wreck diving videos.

Yes, to be blunt you probably couldn't do most of the dives were doing but most experienced commercial guys I know could easily jump right in to most technical diving environments without missing a beat.

 

[rjack321]

Yes, to be blunt you probably couldn't do most of the dives were doing but most experienced commercial guys I know could easily jump right in to most technical diving environments without missing a beat.

Kinda like the 2 KY guys who decided that they didn't need cave training, nor a working END anywhere close to sane to dive Eagle's Nest? One came back, but he's not talking much about their nifty "plan".

Go ahead, poke the Tiger.

 

[MaxBottomtime]

I just don't get why you're making the dive if you have to do it with severely limited cognitive functions. I dive for fun. I want to really remember the dive. I want (for myself, my family, and my teammates) to know that I'll have a very clear mind when the stakes for bad decisions are great. I want to be able to make VERY creative decisions at maximum depth (complex navigation, limited vis, dark water, running line, scootering, avoiding entanglements, tracking deco, shooting video, keeping the team together, accomplishing tasks, making penetrations, etc).

I guess it comes down to what you hope to get out of the dive. I'd be bored silly if I had to "manage" narcosis and limit myself accordingly.

This is the only issue I have with DIR, the dogma. I don't have nearly the number of deep air dives as some of the posters in this thread, but have a few hundred more than the nuvo DIR types. I have never made a dive where I forgot any part of it. I've never been so narced that I couldn't read my spg and know which way was up. If I was planning a dive involving the complicated scenarios you mentioned I would likely use trimix, but for a dive when I'm just going to look around or shoot some video I manage fine on air. Most of the divers I know who use scooters are simply playing underwater. Practicing the skills to make a mile penetration in a 300 foot deep cave is one thing, but if I only dive reefs and wrecks in SoCal I can do that with minimal gear and air, sometimes even solo. It's all about enjoying the dive. Some enjoy military precision-type team diving, some of us like to study marine life. To each their own.