Deep Diving 108 feet w/ a single AL 80 (Air.) No redundancy.

[RyanT]

@ChuckP, as I mentioned, I'm deco trained, and was wearing double 100s. It was a wreck I've been on before, so I thought I had a good handle on navigation. It was also a dive where I had previously not felt narced. That day was a bit colder and darker than normal, so that apparently brought on a bit more narc than anticipated. My point was simply that sometimes conditions that you anticipate can turn out to be a bit different. Good gas reserves and diving within my limits gave me options. I'm glad to hear your decisions underwater have been flawless.

I'll say again, the point of this thread is making decisions about how much gas to bring on a dive. Feel free to roast me for recommending more gas on a dive.

 

[Blackcrusader]

Sorry I missed the fact that it was in cold water. That changes everything. In tropical waters, I still believe it can be safe. I remember one dive when my RMV was probably around 30 l/ min because of a drink party a few hours before and less than 4 hours sleep. Before I got into water, I knew I was not good. When in the water, I immediately realized that I could not control my breathing as well as I did a few dives before. Had it been a deep dive, I would have called it but it was pretty much a leisure dive above 15 meters. I remember that I had 70 bars left from 200 when my wife had 120. I learnt an important lesson that day... and I am still learning.

Dody I stay away from people who party and then want to go on dives. In fact I know many dive centers with breathalyzers who would give you a test. Many have zero policy and don't let divers who are still shitfaced go out on dives or continue with courses. If you have a low blood sugar level and get into difficulties in a current you can simply pass out and drown. You air consumption becomes irrelevant. People think oh it's only a shallow 15m dive it will be fine. Next time you know not to go on the dive at all and avoid being another plaque on the wall.

 

[Blackcrusader]

Being good on air is not a competition. I do around 35 - 50 dives per vacation trip and do several trips a year normally.
Not this year of course still diving but not a lot where I live. So I have the benefit of doing repeat dives 3 or 4 a day over 2 or 3 weeks.
If you can get to do diving like this you will improve a lot if you can dive with more experienced divers.

 

[happy-diver]

Now ain't that a fact!

It is one reason why I find "anchor diving" stressful.

Especially with those poor excuses for captains that grunt groan and fart
their displeasure at having to start the boat, travel a few yards to get you

 

[ChuckP]

@ChuckP, as I mentioned, I'm deco trained, and was wearing double 100s. It was a wreck I've been on before, so I thought I had a good handle on navigation. It was also a dive where I had previously not felt narced. That day was a bit colder and darker than normal, so that apparently brought on a bit more narc than anticipated. My point was simply that sometimes conditions that you anticipate can turn out to be a bit different. Good gas reserves and diving within my limits gave me options. I'm glad to hear your decisions underwater have been flawless.

I'll say again, the point of this thread is making decisions about how much gas to bring on a dive. Feel free to roast me for recommending more gas on a dive.

Yes this is in the advanced thread and the question is about diving 108' on an Aluminum 80 - is it safe?

If sitting on the boat, you don't have a plan or pre thoughts in what you will do if A, B or C happen - doesn't matter how much gas you have.

My main disagreement - and I'm willing to bet that you deal with it in some way - the idea that being narced, especially earlier than normal, and forging ahead with any dive no matter what gas you have is a good idea. I just don't buy the idea that narcosis and more gas makes it better. It's just not something I would post as an example.

Part of the plan on any deeper dive should be how am I gonna evaluate myself for narcosis and what will I do if I don't feel perfect. The thought that well, I'm ok because I have more gas and it'll give me more time - and I really don't think you mean it 100% in the way I'm saying it - isn't something that we should be suggesting to anyone.

 

[RyanT]

On a sub 100' dive, more gas is always better. Do with that as you will.

 

[Blackcrusader]

On a sub 100' dive, more gas is always better. Do with that as you will.

Lets do this, give those OW divers going to 20m the AL 80 with 210 bar, give those going to 30m an AL100 with 210 bar and those going deeper a steel 120 with 230 bar. Now if these are all recreational dives not exceeding NDL we should all be fine

 

[johndiver999]

Yes this is in the advanced thread and the question is about diving 108' on an Aluminum 80 - is it safe?

Part of the plan on any deeper dive should be how am I gonna evaluate myself for narcosis and what will I do if I don't feel perfect. The thought that well, I'm ok because I have more gas and it'll give me more time - and I really don't think you mean it 100% in the way I'm saying it - isn't something that we should be suggesting to anyone.

On a "deeper" dive maybe deeper than 108 (or 130) I KNOW I am not going to fell "perfect". I 100% expect to be impaired by narcosis.

That is a huge part of preparing for the dive, In fact, one of the tools I use to judge the severity of my impairment is if/when I actually do "feel perfect". Once I reach a situation where I forget that I am impaired (or "feel perfect") then I try to use that as a very strong signal that I am not dealing with the narcosis properly and might even consider ending the dive early. In any case, I use it as a strong wake up call that I need to regain my focus and be more self- aware and cognizant of my narcosis.

And of course, having a ton of extra gas is always nice because you are too stupid to be doing really precise calculations that you want to bet your life on. Having a margin of available gas is a very significant resource to have on a deeper dive and having too little (or a very minimal) buffer just makes everything harder and more stressful. I'm not sure why this later concept even warrants a discussion?

 

[Celt]

the idea that being narced, especially earlier than normal, and forging ahead

That’s actually how narcosis hits me. I get an initial hit when I get to the bottom so I give a minute or two checking my gear till it clears and then carry on with the dive. A fast drop in cold dark water will do that.

 

[Oldbear]

Hello. I was thinking back over the years. I worked for a Dive shop years ago as a Divemaster.
We did our deep dives on the Chester Poling off Gloucester, Mass. for the P.A.D.I. Advanced Open Water Course.
At high tide the the wreck sits in 108fsw. It always amazed me that people would do this dive "Normally." on single aluminum 80's without any type of redundancy.
I always thought it was insane???? Divers would come back on board with extremely low pressure readings on their gauges. Too me, it left no room for error, or any type of contingency whatsoever. At that time, I was diving with an Aluminum 100 cubic 3300 P.S.I. (Air.) with a 30 cubic pony bottle.(Air.)
20 years ago the shop did not have "Nitrox." (This is not an enriched air scenario.)
Staying within N.D.L.......I don't care how long you've been diving, or if, your'e the best breather on the planet your max bottom time is approximately 18 to 20 minutes, at 100fsw, not including the 3 min Safety stop.
So, I was curious? The question is: Would you personally make this dive, staying within N.D.L. on air........No redundancy?
Cheers.

On Kwajalein we do about 450-500 of these types of dives per month. No issues...