85m air dive

[Hank49]

.I am one of the people whose time you are wasting.

The only person wasting YOUR time is you. Let it go. If you get this upset over every deep air dive on Scubaboard you're going to need hypertension medication soon.

 

[ScubaSteve]

......Let it go. If you get this upset over every deep air dive on Scubaboard......

Consider it done. I have no issue with deep air......I'll observe until the OP finally admits that he refuses to answer because he does not know.

 

[SC_Hoaty]

Tortuga68 -I'm dead ignorant on this type of diving. It sounds like you had support divers between you and the surface, and (did I get this right?) two others with you at depth.

In the event something developed at depth that took some problem solving, was the time to correct something worked into the plan? OR would that just change the deco schedule, and use more air (presuming there was more air available)?

 

[mike_s]

Hear ye, hear ye! The kangaroo court of scubaboard is now in session, judge ScubaSteve presiding. Tortuga68, you stand before us accused of being a TROLL! If you fail to answer all and any of our questions completely and thoroughly, now matter how mundane or irrelevant, you will be found GUILTY by this court and sentanced to... to, umm... to having ScubaSteve and I SHAKE OUR HEADS at you vigorously

No no, do go on

 

[Rhone Man]

I guess my question for the OP though is what is the narcosis like at that depth? Did you have the deco bottles with you or were they suspended on a line or carried by the support divers? The idea of being at 275', with the mental ability of a turnip, and then having to decide which regulator to use would scare the hell out of me.

It says a lot about Scubaboard that someone posts that they have completed... ok, let's call it an "interesting dive", and then we get 50 posts debating whether the OP (who is reasonably well known on the board) is trolling or not, before post #51 is the first attempt by someone else to take something positive from being able to discuss the OP's experience.

Hey, I don't like the fact the fact that they used to force US navy sailors to breathe pure O2 in hyperbaric chambers until they blacked out, or the Haldane exploded goats, but I am happy to read the research and see what I can learn from it. You can hate deep air all you like, and you can hate guys who are proud of having done dives like that all you like, but there is a lot of interesting ground to cover when you finally finish bitching about it.

Waaaayyy too many people around here just spoiling for a fight.

EDIT: Bugger, it just occurs to me that this post is just as guilty as those I lambast. Frick.

 

[Sas]

Yes, I do. Skills can be trained so that the become reflexive - I can do a valve shutdown okay for example - but problem solving is an issue, you can get task focussed, perceptual narrowing etc. But I wouldn't say I worry about it.

How did your deep air training prepare you for problem solving? I know you can learn skills really well, but just wondering what you would do if faced with a big problem. Or do you just make a calculated risk knowing that it is not common for something to go wrong when diving?

A combination of reasons - I'm interested to see what my limitations are, how well I do or don't function at depth. I know it can be done with what I consider a reasonable degree of safety by the right people in the right conditins with the right training, support, work-up, equipment etc

So, is that it for this type of diving or what will you do now?

 

[Tortuga68]

I'll observe until the OP finally admits that he refuses to answer because he does not know

Like they told you in your OW class - don't hold your breath

It sounds like you had support divers between you and the surface, and (did I get this right?) two others with you at depth.

In the event something developed at depth that took some problem solving, was the time to correct something worked into the plan? OR would that just change the deco schedule, and use more air (presuming there was more air available)?

There were only two divers (me and my buddy) on the actual 85m dive. Two support divers waited for us at 40m (between us and the surface)

For dives like this we usually make two contingency plans, one for over time and one for over depth (eg we planned 8 minutes bottom time and 85m maximum depth; so we would also cut run times with deco plans for 10 minutes & 85m, and 8 minutes & 87m). The difference is in the deco schedule as you said, time is added to some of the stops, which of course means you need more of whichever gas you are using at those stops, ie in this case 85-21m air, 21-6m 50%, 6m 100%

Since we were each carrying roughly double the amount of each gas that we needed for the plan (including the support divers) we had plenty of gas for contingency

 

[Tortuga68]

How did your deep air training prepare you for problem solving? I know you can learn skills really well, but just wondering what you would do if faced with a big problem. Or do you just make a calculated risk knowing that it is not common for something to go wrong when diving?

We do practice different scenarios, but at shallower depths. I don't like doing drills below ~45m. So it's hard to know how you would react, except that it would be slower/less intelligently than at a shallower depth. I do believe that regular repeated exposure improves your capabilities. We have redundant everything and work as a team. So it's a calculated risk that we would be able to deal with most problems that might occur

So, is that it for this type of diving or what will you do now?

I'll continue to do deep air when I'm in the Philippines (since that's where my tech gear and buddy are). It's getting to the point now where we need to spend a week doing work-up dives, so time is a factor in going deeper. However I would like to try 90m next. I'm currently drawing a line in the sand at 100m which I don't want to cross

Another thing I want to do at some point is to dive trimix to whatever my maximum depth on air has been, to compare the difference

 

[SC_Hoaty]

There were only two divers (me and my buddy) on the actual 85m dive. Two support divers waited for us at 40m (between us and the surface)

Thanks - I thought it was you, your buddy, and the instructor. I must be remembering the Narcosis course posts (since I read these both to try to understand this thread better).

For dives like this we usually make two contingency plans, one for over time and one for over depth (eg we planned 8 minutes bottom time and 85m maximum depth; so we would also cut run times with deco plans for 10 minutes & 85m, and 8 minutes & 87m). The difference is in the deco schedule as you said, time is added to some of the stops, which of course means you need more of whichever gas you are using at those stops, ie in this case 85-21m air, 21-6m 50%, 6m 100%

Since we were each carrying roughly double the amount of each gas that we needed for the plan (including the support divers) we had plenty of gas for contingency

So if I understand the planning, you have pre-planned to deal with a 2 minute problem, and carry redundant air so that if you need to stay at depth longer, you should be OK, and then replan deco after you have ascended to where narcosis effects are reduced. If the issue is an air issue, you have a buddy who is carrying more air. Is the risk then in two categories - narcosis will slow responses to problems, and OxTox, where you're pretty much toast anyhow?

We do practice different scenarios, but at shallower depths. I don't like doing drills below ~45m. So it's hard to know how you would react, except that it would be slower/less intelligently than at a shallower depth. I do believe that regular repeated exposure improves your capabilities. We have redundant everything and work as a team. So it's a calculated risk that we would be able to deal with most problems that might occur

So you determine the likely problems (that are recoverable) and then practice the skills at shallower depths so they become more reflexive, and less intuitive? (Maybe wrong words - I mean it becomes less "thinking" involved since you can't count on the clear thinking due to narcosis. Is this right?)

I say "that are recoverable" since something like OxTox in a team members is probably the end of the road for that person (due to drowning). Am I misunderstanding this?

I'll continue to do deep air when I'm in the Philippines (since that's where my tech gear and buddy are). It's getting to the point now where we need to spend a week doing work-up dives, so time is a factor in going deeper. However I would like to try 90m next. I'm currently drawing a line in the sand at 100m which I don't want to cross

Another thing I want to do at some point is to dive trimix to whatever my maximum depth on air has been, to compare the difference

Is there an external (by this I mean data/research by others) reason for the 100m limit, or is that your personal preference? I ask since you are WAY outside my comfort zone, but I'm a frickin' newbie compared to many on ScubaBoard, and thus my comfort zone is a LOT smaller (and shallower!). Is 100m some sort of "magic" limit (as other depths are for OW and AOW divers)?

 

[Tortuga68]

Thanks - I thought it was you, your buddy, and the instructor. I must be remembering the Narcosis course posts (since I read these both to try to understand this thread better)

There were three of us on the final 73m NM course dive; me and two instructors. The 85m dive was just me and my buddy (who incidentally is an instructor, but was not acting in that capacity)

So if I understand the planning, you have pre-planned to deal with a 2 minute problem, and carry redundant air so that if you need to stay at depth longer, you should be OK, and then replan deco after you have ascended to where narcosis effects are reduced

Not exactly... we had already done the deco plan for the two contingencies. However if we had gone beyond either of them, then yes we would have replanned the deco at our first stop ~40m

If the issue is an air issue, you have a buddy who is carrying more air. Is the risk then in two categories - narcosis will slow responses to problems, and OxTox, where you're pretty much toast anyhow?

I'd say they were the two primary risks, yes

So you determine the likely problems (that are recoverable) and then practice the skills at shallower depths so they become more reflexive, and less intuitive? (Maybe wrong words - I mean it becomes less "thinking" involved since you can't count on the clear thinking due to narcosis. Is this right?)

Correct. For example a possible problem would be a gas leak from a reg, hose, gauge etc. We practice manifold shutdown drills repeatedly at various depths <50m

I say "that are recoverable" since something like OxTox in a team members is probably the end of the road for that person (due to drowning). Am I misunderstanding this?

If you have a seizure at depth and your reg comes out, you're most likely going to drown. Some people use bungees to hold the reg in their mouths, or a full-face mask to mitigate this risk

Is there an external (by this I mean data/research by others) reason for the 100m limit, or is that your personal preference? Is 100m some sort of "magic" limit (as other depths are for OW and AOW divers)?

The generally accepted "magic" number for air is 66m, as that's where you reach a PPO2 of 1.6ATA, although some people prefer to stick to 1.4, 1.2 or even 1.0ATA for their dive planning

I just like round numbers