Reason for Rec Triox?

[KMD]

I don't think you'd find many DIR divers using air at 100', but conceptually the point is that we agree on a baseline, let's say we all agree that dives to 100' we'd use 32% and on dives below 100' we all agree to use 30/30. Then that becomes part of our team protocols and we'd move on from there. Once the team starts accepting compromises where and when does it end? Now I agree that this is in a perfect world, so for example if we all went to Cayman, and He is over a $1 per CuFt it may be cost prohibitive to do a week of diving on 30/30 and we'd accept a 32%, but again that would be a team decision. Moreover, we dive in teams of 2 all the time so I'm not sure where you get the impression we insist on 3 man teams.

MHK - What happens if say you are on a 7 day livaboard and on the second day, the captain comes up to to and regretfully explains that their membrane system has broken down and they can only supply you with air. Would you dive but at a reduced level or would you become a sun bather for the rest of the trip?

Note I dont ask this as trying to get a "gotcha" but more of what would you do in a real life situation. This is where the rubber meets the road.

As for me this situation recently came up. The DM at the resort appologetically explained to me that both of their anylizers were failing to agree on calibrations. As they were partial pressure blending they had to pull the offer of nitrox off their services. For me I had to decide whether I was going to do any further diving that trip. I ended up mentally deciding to do so, but set my limits to a max depth of 60' for 45 minutes. The epilog of the story was that because of weather I didnt do any more dives anyways.

 

[SparticleBrane]

...and that's why you bring your own analyzer.
I have zero issues diving air. I get air for free, nitrox costs money. Simple as that. My dives recently have all been shallower than 60ft in a rock quarry. There's no reason to use nitrox on dives like that.

 

[rjack321]

MHK - What happens if say you are on a 7 day livaboard and on the second day, the captain comes up to to and regretfully explains that their membrane system has broken down and they can only supply you with air. Would you dive but at a reduced level or would you become a sun bather for the rest of the trip?

Note I dont ask this as trying to get a "gotcha" but more of what would you do in a real life situation. This is where the rubber meets the road.

As for me this situation recently came up. The DM at the resort appologetically explained to me that both of their anylizers were failing to agree on calibrations. As they were partial pressure blending they had to pull the offer of nitrox off their services. For me I had to decide whether I was going to do any further diving that trip. I ended up mentally deciding to do so, but set my limits to a max depth of 60' for 45 minutes. The epilog of the story was that because of weather I didnt do any more dives anyways.

Just tailor your dives and exposures to the resources you have available. Which in some cases might mean sitting out a dive or even all of them. e.g. No one's saying 30/30 is the only mix to use on a 90ft dive. Nice though.

Vs. I don't see myself doing a 120 ft penetration dive without helium. Too much chance of having a life threatening issue while impaired.

 

[Dive-aholic]

And really, it's not as strict as you point out (which is what I think MHK is getting at).
The critical thing is that you dive "compatible" gases and/or profiles within the DIR ranges.

I never thought DIR was that strict. What I've seen is that some DIR divers are strict. I do understand the compatible gasses issue.

Moreover, we dive in teams of 2 all the time so I'm not sure where you get the impression we insist on 3 man teams.

From divers like the ones I just mentioned stating things like limeyx did here:

DIR does not "dictate" a team of 3, but once you do tech1 or cave1 and see what the options are with one OOA diver in a team of 3, compared to a team of two (of course taking into account that in theory with 3 divers the chance of a failure might be a bit higher), you can see why 3 is considered safer.

only those divers take this and make it a mandate in their diving.

DIR divers dive with non-DIR people all the time. Shallow dives, skills dives, simple dives in general are fine to do with mixed teams, when you understand that that's what you are doing.

Lynne, I realize that. But I also realize that some DIR divers won't dive with non-DIR divers. I just wanted clarification on MHK's statement

My guess is that, in many ways, you and your wife are already functioning as that kind of team. You're making some gas decisions that wouldn't be DIR, though, because the risks involved in that degree of narcosis aren't recommended in the DIR protocols.

We do dive as a team, pretty much to the point where we know what the other is doing or going to do and we can have entire conversations underwater and understand each other completely with minimal signing. Our gear is also configured identically to each other and probably (from what I know about DIR) 90% DIR. But we do like to "test the waters" on occasion. Of course, this only happens when we're diving with no one else, in familiar locations, and in agreement on what we're going to do.

 

[limeyx]

I never thought DIR was that strict. What I've seen is that some DIR divers are strict. I do understand the compatible gasses issue.



From divers like the ones I just mentioned stating things like limeyx did here:



only those divers take this and make it a mandate in their diving.



Lynne, I realize that. But I also realize that some DIR divers won't dive with non-DIR divers. I just wanted clarification on MHK's statement



We do dive as a team, pretty much to the point where we know what the other is doing or going to do and we can have entire conversations underwater and understand each other completely with minimal signing. Our gear is also configured identically to each other and probably (from what I know about DIR) 90% DIR. But we do like to "test the waters" on occasion. Of course, this only happens when we're diving with no one else, in familiar locations, and in agreement on what we're going to do.

But just because "some" divers who have GUE/DIR training do it, does not make it a requirement of DIR.

What if I said "some PADI divers like to dive with an air2, or with no octo, or solo" does that make PADI itself require any of those things?

No. Obviously GUE cannot guarantee that every student will behave the same way after passing a class, despite every effort they make to try to educate people.

Teams of 3 do have safety benefits, but teams of 2 are fine too -- you just have to weigh up the situation and plan accordingly (for instance, if you are penetrating with a team of 2, you dive a bit more conservatively on the gas plan etc.)

Regarding not diving with DIR divers -- it depends. Recreationally, I think you will find a lot of DIR divers will dive with pretty much anyone (although if a diver has an unsafe attitude, then probably not).

For a tech dive, I am going to limit my buddies not just to DIR divers, but to DIR divers that I know and trust -- this is the way of things, but it's about diver safety, compatible procedures etc. rather than simply "not diving with DIR divers"

 

[MHK]

But I also realize that some DIR divers won't dive with non-DIR divers. I just wanted clarification on MHK's statement
.

I dive with non-DIR diver's all the time. However I will caveat that point by saying that I restrict those dives to 30' and we do a thorough pre-dive briefing. More often then not I'm approached by non-DIR divers to "show them" how we dive. In such a case, there is no reason to go deep. However, if I were doing a cave dive, tech dive and/or a substantial recreational type dive I would limit my diving to those share the same mindset.

Hope that helps..

 

[Dive-aholic]

But just because "some" divers who have GUE/DIR training do it, does not make it a requirement of DIR.

True, but not being DIR, I don't know any different than what I hear or read about it. I've seen the 3 person team comments, but never 2 person team comments. That's why I'm here - to learn.

For a tech dive, I am going to limit my buddies not just to DIR divers, but to DIR divers that I know and trust -- this is the way of things, but it's about diver safety, compatible procedures etc. rather than simply "not diving with DIR divers"

I do the same, with the exception of the DIR part. I limit my dive buddies on deco dives to divers I know and trust. I will do a cave dive with someone I haven't cave dived with before, but I will be a little more conservative. And that would most likely be in a 3-person team anyway since my wife would be along.