Sometime – It’s Just One Things After Another

[Northeastwrecks]

Hanging a bottle at 15' is a good thing. Unless you seriously go over the NDL your deco obligations start at 20' (see DCIEM tables). A hang tank at '15 with a 6' reg hose can easily accomodate this. In our experience the tank is rarely used and when it is, it's because someone had dipped below the 500psi mark and wanted to comfortably complete their safety stop.

No religious war is necessary. However, what do you do if you are surfacing off the line or if the hang tank regs malfunction?

In addition, tables that calculate based entirely upon shallow stops don't factor in microbubbles and the nitrogen free gas phase.

The instructors at my LDS teach our recreational level students how to calculate deep stops to account for this. Of course, we also include them in our decompression planning.

2) Yes it IS possible to surface with 500psi. Our certifying agency teaches to begin final ascent with no less than 500, but our club policy is to try and surface with 500psi (lest you suffer the scournful stare of the DM). This does two things, it gives you an extra safety buffer and secondly it requires you to understand your rate of air consumption. As Mr. Northeastwreck indirectly pointed out, only with practice can you understand what you need to leave with given the depth and conditions in order to make it out with 500psi. Mr. Northeastwreck, if I can manage it surely someone with your diving experience can!

I'm not going to comment upon the agency policy of starting an ascent with 500 psi, except to ask what you would do in this situation.

You and a buddy are on a wreck at 110 fsw. You both have 500 psi. You start your ascent. All of a sudden, a solo diver rips your reg out of your mouth and starts hoovering through your gas supply. Do you have enough gas to ascend at a safe rate while making all required and or recommended stops, assuming a SAC rate of 1.0 for both divers?

With regard to your club's policy, how do you calculate how much gas it will take for you to reach the surface with your target value.

3) If another diver approaches in need of air, buddy or not, I'm going to give it to him! Seriously, what would you do in this situation?! On a safety stop, who cares? It's the end of my dive, I'm heading up too! Do I care if someone other than my buddy is using my emergency reserve of air? Of course not!! I have dived with many newly certified divers. None of them sucked so bad that I would deny another diver, in immediate need of assistance, air because my buddy *might* need it!

What are you going to do when the diver comes to you at 100 fsw and needs your air? Or when your buddy signals OOA and you've already got someone on your primary?

The point is not that you aren't going to share. The point is to consider what you will do when your plan goes down the tubes. Failure analysis and planning, rather than wishful thinking, is needed if you are going to be safe in the water.

4) If for some reason I find myself in need of air AND for some other reason my buddy is nowhere to be found AND there is someone else close by, I am going to - with calm - give the OOA signal and ask to share air.

Absolutely. I agree. However, after I get to the surface, I'm going to have a long discussion with my buddy to determine what went wrong. I'm also not going to applaud myself or think that it was OK because I made it up alive.

5) Know about the factors affecting nitrogen loading that your dive computer cannot calculate for. As Mr. Northwestwrecks vaguely put it "[decompression diving] requires skills beyond looking at your computer and hoping that it has properly calculated your obligation" Many divers use the dive computer to take advantage of dynamically calculating a multi-level profile thereby extend their bottom time, or as ShakaZulu described as "Riding the NDL curve" Doing this reduces the margin of error since the computer calculates for depth, time and maybe altitude and temperature. Dr. David Sawatzky wrote a good article in Diver magazine on this topic (I think it was in the Nov 2003 issue). Things like fatigue, hydration, physical conditioning, age, have an effect on nitrogen loading and must be taken into consideration.

Your statement is correct as far as it goes. However, its totally irrelevant.

I don't use a dive computer to track decompression dives or to give me my stops. However, I believe that you'll find that decompression divers who rely upon computers to track their dives don't simply jump in the water, wait for the computer to start beeping, then do what it says.

You still need to know, in advance, what your run time will be for a dive. This allows to calculate your gas reserves and determine whether you will have enough gas to execute the dive. You need to calculate your rock bottom. You need to calculate deco stops without deco gas and determine whether you will have enough gas if you lose your deco bottles. You need to be able to handle the situation if your computer fails or if your equipment fails.

The point is that having a computer is no excuse for exceeding the limits of your training for from obtaining proper training before engaging in more advanced dives.

6) Training and practice!!! I agree that proper SCUBA training has suffered. Weekend OWD certifications seem to be replacing 12 week (18hrs classroom, 18hrs pool and 7 o/w dives) OWD certifications. IMHO, a weekend is not enough to pick up the skills and knowledge required to be a safe diver. Additionally, we encourage club members to help out at the pool during classes which also serves to maintain their skills.

I agree that there could be more to OW training. However, even a 12 week course would not equip a diver for decompression or other overhead dives.

From the near misses I've read so far from those brave enough to post them, none have been what I would classify as accidents and only a few that might qualify as incidents. I suspect that the people that frequent this site are avid divers with a keen interest in safety. Are mistakes made? Of course, we're human. I'm also sure we all have our stories of the occasional bone-headed move, including Mr. Northeastwreck.

Count on it. However, after each incident, I try to identify and correct the root cause.

In this case, the root cause of the problem is a combination of inexperience, malfunctioning equipment and an unsafe attitude.

 

[MikeFerrara]

Well Don if I've ever in my life seen a good time for an "I told you so" (or 10 or 12) this would be it.

Several of us tried to tell you about back mounted pony bottles. You've put up post after post about your great experiences with it yet the very first time you need it it's of no use to you.

We've tried to explain gas management and decompression too.

The pappose is a wreck that I'd dive with my doubles and one decompression gas. The wreck is too deep to get much of a dive without planned decompression so I'd plan on it. I would have enough gas to bail some one like you out although my days of diving wrecks like the Pappoose off recreational boats are long gone so it's not likely that I'd have to.

Your habit of diving solo (sort of) without the planning or equipment to really dive solo with the backup plan of latching on to some unsuspecting team is a blatant endagerment of every one else on the boat.

I really think you should stay shallow, in good conditions and with a good buddy until you get some additional training.

 

[diverbrian]

I have my share of bone headed incidents as well. I don't post most of them here, but I do discuss them with people that I dive with. As NEW says, there is more to any dive than jumping in until my computer hits a certain amount of deco/NDL time and heading back at that point. I am sure that Don knows this as well. Normally, I am going by run time and have calculated how much gas I will need to start with (or know this from experience- which seems to be the case more often anymore).

There are issues involved with heavier currents as well. I am guessing that whichever wreck Don was diving in NC had some pretty swift current along the line. I know this by conversations with another diver who dives the same wrecks and tells me that one of the cardinal rules out there is not to let go of the ascent/descent line on ascent/descent. It can be difficult to keep from being blown away from the wreck. One of that diver's incidents has been told to me and it involves getting blown off the wreck with the boat having to follow her lift bag (with her under it).

Having said all this....

It would behoove most of us to get an idea of our normal RMV (basically our surface breathing volume rate measured in volume used/min.). This is a must in any courses involving deep diving. It really should be done for most Open Water training, but sadly many instructors won't take the time.

I will be honest in saying that what most people here call rock bottom, I was trained to call turn pressure. Turn pressure for a dive plan should be calculated before the diver hits the water.

Now, if a diver screws up and the plan is violated, what is the next thing that we ask? Don't grab my regulator in a panic and turn the dive into an episode of Sea Hunt where my dive knife turns into a defense tool. Here again, once a dive plan is screwed up we need to remember that the only real emergency is out of air.

Would it have been anything more than embarrassing to come up the wrong line? Instead, Don thought that he had enough to swim along and hope that the other divers in his group were heading for the right one when he was running light on gas. Apparently, this was the phase of the dive where he incurred the unplanned for deco obligation. By his orginal plan he should have been ascending by then. Did this aggravate the situation? Probably. Was it fatal? Only if he outright panicked. He noticed that he was running low on gas and switched to the pony bottle. By rights, this should have solved the issue. Nineteen cubic ft. of gas will get most people to the surface, even with a light deco obligation. Didn't happen due to a leak on the first stage. He didn't have the gas reserve that he thought that he had or he was breathing more air than he thought and maybe nineteen cubic ft is not enough. Likely it is a combination of these factors.

So, he switches back to the limited back gas. Once he runs out of that I see two options. They are flag someone down to share air with or CESA. I have read about enough CF dives in NEW's neck of the woods to know that surfacing without some form of deco is a great way to have chopper's services become required. So, he found someone with enough gas to split with him to kill off the deco. And while some experience in deco tells me that the deep stops are great, I'll take what clears the computer if that is all that I can get.

Personally, on the dives that I am involved with that use emergency hang bottles we tie them off near the wreck on the bottom and the DM is the last person to start their ascent. The DM or designated person picks up the bottle on the way up. This allows for someone to use the bottle that may want to do a slow ascent. We have not had one of those bottles used to my experience nor do we even employ them that often. We would rather that our divers trust good gas management than a safety blanket that NEW correctly points out may be impossible to get to depending on where the low on gas incident occurs on the wreck.

Now, like many dive incidents I see many points of failure. But, like Denny I normally carry enough backgas to comfortably get myself and a buddy up. I don't have an issue with sharing air like that unless the person is liable to get my buddy team hurt. What is important at the end is that Don surfaced and had the guts to tell us his thoughts while he was down there. Even he admits that he messed up, but at least he has a chance to review where he messed up and to let us all learn from it.

 

[DandyDon]

Life is not a journey to the grave with the intention of arriving safely in a pretty
and well-preserved body, but rather to skid in broadside, thoroughly used up,
totally worn out, and loudly proclaiming "WOW----WHAT A RIDE!!!"

I've always liked that. Did you write that, or do you have the source?

Several of us tried to tell you about back mounted pony bottles. You've put up post after post about your great experiences with it yet the very first time you need it it's of no use to you.

Yeah, my practice in the past has been to check the pressure on the Pony before the dive to ensure it was available, leave it on for test breathing, and more recently - now that I hang it upside down where I can easily - turn it off until I may need it for bail-out of myself or someone else. Mine has never been intended to be a part of the dive plan, nor a deco bottle; just a spare, with more to offer than a Spare Air.

The arquements for hanging it on a sling given in the past here on SB were always so I could pass it off - an action I continue to reject. Are you now suggesting another reason to sling it is so I can watch it for problems more easily? That just might be a good idea, not heretofore offered. But it was not my mounting or the Pony itself that failed me; it was the reg.

Since the pass-off suggestion was never compatible with my diving, and no other suggestions for the pony had been previously offered, I have been left with learning more from experiences, and - pushing limits is certainly a learning opportunity. Previously offering me arguements to the tune of "my way or else" offers little to be open minded. One short range plan for me is to get in the pool as soon as I have replaced my faulty pony reg and practice checking on it more closely in its current position.

Nonetheless, even though the proponents of slinging the pony on my side never offered this reasoning that I can recall, I am now certainly considering doing so based on this experience, which could indeed repeat itself before I hang up the fins for old age or other reasons.

The pappose is a wreck that I'd dive with my doubles and one decompression gas. The wreck is too deep to get much of a dive without planned decompression so I'd plan on it. I would have enough gas to bail some one like you out although my days of diving wrecks like the Pappoose off recreational boats are long gone so it's not likely that I'd have to.

At 115 feet, like other wrecks commonly dived by Recreational divers off of NC and very commonly dived off of Florida, can be approached in a range of plans. For me, diving a 120 cf tank alone gives an abundance of gas that I should need to dive the wreck to NDL, then do a slow ascent on the anchor line, make a couple of deep stops, then hang out on the hang line for an extended time wathcing baracudas and jellies until the computer works it way back out of the Yellow to Green. For that plan, the Pony seems quite sufficient as a bail-out bottle not expected to be used, while your suggested plan certainly goes well beyond my intentions.

I'll agree that a wide range of choices exists on how to plan the dive - from one extreme of diving a 80 cf tank and returning to the boat with 100 psi (the kind of divers that prompted to carry a pony), to not getting in the water at all. I'd certainly want to avoid both extremes, yet - your gas load for a 115 ft dive sounds pretty extreme as well. My dive plan, such that it was, went to caca only when I failed to locate the anchor line in the cloud of bait fish, which has never happened to me before, and when my pony reg failed - both problems I can certainly learn much from surviving on how to prevent.

The one thing I got right - which I'd like to expand on for those who may want to learn from my challenges - is that things will wrong, with a plan, with equipment, with the dive itself, yet - Panic is not an option to be accepted. Think out the other options in advance, with study, training, practice, etc, quickly and repeatedly reivew the inventory of options in a descending order, and continue to excecute the next, seeminly best action.

 

[diverbrian]

Well Don if I've ever in my life seen a good time for an "I told you so" (or 10 or 12) this would be it.

Several of us tried to tell you about back mounted pony bottles. You've put up post after post about your great experiences with it yet the very first time you need it it's of no use to you.

We've tried to explain gas management and decompression too.

The pappose is a wreck that I'd dive with my doubles and one decompression gas. The wreck is too deep to get much of a dive without planned decompression so I'd plan on it. I would have enough gas to bail some one like you out although my days of diving wrecks like the Pappoose off recreational boats are long gone so it's not likely that I'd have to.

Your habit of diving solo (sort of) without the planning or equipment to really dive solo with the backup plan of latching on to some unsuspecting team is a blatant endagerment of every one else on the boat.

I really think you should stay shallow, in good conditions and with a good buddy until you get some additional training.

I am not familar with the wreck as I don't get to dive warmer salt water often. Like you, I try to avoid diving deeper wrecks off a recreational boat.

While I agree with you about diving solo without proper planning, I would like to see people admit to their mistakes so that we can have conversations like this with the person involved instead of their next of kin. As you said, I may not like it. But the possibility is in the corner of my mind that I may have to do my best to help somebody out that lands themself in that situation. This sounds like the reason that I do a lot of filling of my doubles with 1000-1500 psi in them at the end of a day even on trips where I didn't have to do rule of thirds. We all do bone-headed things. Saying "I told you so" may be true, but it doesn't use the incident to address the problem.

 

[diverbrian]

At 115 feet, like other wrecks commonly dived by Recreational divers off of NC and very commonly dived off of Florida, can be approached in a range of plans. For me, diving a 120 cf tank alone gives an abundance of gas that I should need to dive the wreck to NDL, then do a slow ascent on the anchor line, make a couple of deep stops, then hang out on the hang line for an extended time wathcing baracudas and jellies until the computer works it way back out of the Yellow to Green. For that plan, the Pony seems quite sufficient as a bail-out bottle not expected to be used, while your suggested plan certainly goes well beyond my intentions.

I'll agree that a wide range of choices exists on how to plan the dive - from one extreme of diving a 80 cf tank and returning to the boat with 100 psi (the kind of divers that prompted to carry a pony), to not getting in the water at all. I'd certainly want to avoid both extremes, yet - your gas load for a 115 ft dive sounds pretty extreme as well. My dive plan, such that it was, went to caca only when I failed to locate the anchor line in the cloud of bait fish, which has never happened to me before, and when my pony reg failed - both problems I can certainly learn much from surviving on how to prevent.

That is part of the reason that people like Mike do deco training. I am another one like this. Yes, doing the dive on an eighty is worse than with a 120 cu. foot tank and a pony. No, that is NOT an excessive amount of gas for a 120 ft. dive. Check your tables and you will find that without going into deco at that depth, your dive time will be extremely limited. The minute that you plan a staged deco, you are into rule of thirds gas management. That drives the larger need for the breathing gas.

The one thing I got right - which I'd like to expand on for those who may want to learn from my challenges - is that things will wrong, with a plan, with equipment, with the dive itself, yet - Panic is not an option to be accepted. Think out the other options in advance, with study, training, practice, etc, quickly and repeatedly reivew the inventory of options in a descending order, and continue to excecute the next, seeminly best action.

Agree! Panic kills. I didn't see any of that in the narrative. If you had panicked, you likely wouldn't have found someone to share gas with you and we would be guessing at everything that you did right or wrong (as you wouldn't be around to tell us) instead of getting it from the most important source... the diver involved with the incident.

 

[Northeastwrecks]

DandyDon:

In the end, what this really comes down to is:

1. What were the root causes of your incident?

2. What are you going to do to prevent this from happening again?

3. Could anything have been done to manage the rescue in a manner that would have been safer for those involved?

 

[beachdivequeenbelam]

Thanks Tiggrr, Denny, BDQB and others who have been nice here....

I knew I'd take some thumping from some membes here, but I wanted to share in hopes of helping others, anyway. And like I said...

"The good news, I now realize that I'm not as good of a diver as I thought I was and now realize that I do need a lot of work!"

Your Welcome!!
But I want to thank you again for sharing because I just signed up for Decon and tech classes to avoid this because of your experience. It is very clear you can never know what may happen on a dive. What if you have to go deeper to rescue someone or something happens and someone panics and pulls you down. There are no guarantees when you are underwater no matter who you are diving with. I want to know I have the knowledge to keep myself safe first and then if I am rescuing someone I want to keep them safe as well. If I know the theory then I can plan it underwater if need be. You can use an underslate to tell others going up to send down some extra tanks if need be.
Thank you for showing us Knowledge is power and that making mistakes is part of the risks we take diving. I am glad you are safe.

 

[MikeFerrara]

I've always liked that. Did you write that, or do you have the source?

I stole it from a joke email that some one sent me. The author wasn't credited.

Yeah, my practice in the past has been to check the pressure on the Pony before the dive to ensure it was available, leave it on for test breathing, and more recently - now that I hang it upside down where I can easily - turn it off until I may need it for bail-out of myself or someone else. Mine has never been intended to be a part of the dive plan, nor a deco bottle; just a spare, with more to offer than a Spare Air.

The arquements for hanging it on a sling given in the past here on SB were always so I could pass it off - an action I continue to reject. Are you now suggesting another reason to sling it is so I can watch it for problems more easily? That just might be a good idea, not heretofore offered. But it was not my mounting or the Pony itself that failed me; it was the reg
.

There are lots of reasons for slinging it but being able to see it and the SPG (on a short hose where it doesn't clutter up the rest of your configuration) is among them. I, for one (there have been others) have pointed out the importnce that many times.

Regs fail. That's why we use redundancy for some dives.

Since the pass-off suggestion was never compatible with my diving, and no other suggestions for the pony had been previously offered, I have been left with learning more from experiences, and - pushing limits is certainly a learning opportunity. Previously offering me arguements to the tune of "my way or else" offers little to be open minded. One short range plan for me is to get in the pool as soon as I have replaced my faulty pony reg and practice checking on it more closely in its current position.

Being open minded but when it leads to the reinvention of the weel it just isn't practical.

Nonetheless, even though the proponents of slinging the pony on my side never offered this reasoning that I can recall, I am now certainly considering doing so based on this experience, which could indeed repeat itself before I hang up the fins for old age or other reasons.



At 115 feet, like other wrecks commonly dived by Recreational divers off of NC and very commonly dived off of Florida, can be approached in a range of plans. For me, diving a 120 cf tank alone gives an abundance of gas that I should need to dive the wreck to NDL, then do a slow ascent on the anchor line, make a couple of deep stops, then hang out on the hang line for an extended time wathcing baracudas and jellies until the computer works it way back out of the Yellow to Green. For that plan, the Pony seems quite sufficient as a bail-out bottle not expected to be used, while your suggested plan certainly goes well beyond my intentions.

The sand is at about 120. In good conditions when you can stay nearer the top of the wreck (90 ft or so) it's not sich a bad dive but I've been on it when the vis was bad, the current was blowing and you had to stay down behind the wreck...and yes I saw divers run out of gas. We didn't have any trouble but it was a wasted trip. We didn't have a clue at the time and gladly baught a ticket sold to us by a LDS. As a newly minted DM diving with my wife who was a newly minted AOW diver at the time, we hit the bottom and realized that we didn't have the gas or the time to do much so we headed back up without ever going more than a few feet from the line. While hanging around under the boat watching the Jacks and the cuda we were just about run over by all the OOA divers racing for the boat.

I'll agree that a wide range of choices exists on how to plan the dive - from one extreme of diving a 80 cf tank and returning to the boat with 100 psi (the kind of divers that prompted to carry a pony), to not getting in the water at all. I'd certainly want to avoid both extremes, yet - your gas load for a 115 ft dive sounds pretty extreme as well. My dive plan, such that it was, went to caca only when I failed to locate the anchor line in the cloud of bait fish, which has never happened to me before, and when my pony reg failed - both problems I can certainly learn much from surviving on how to prevent.

Loss of the down line is always possible. When you are cutting it close with gas supplies or NDLs you just don't have much time to work things out. Time pressure, especially when there are other problems, is among the worst things to have to deal with because with enough time and gas you can fix just about anything.

As for my gas plan being more than what's needed, Id do a relaxing dive on that wreck with 45 minutes or so of bottom time and have plenty of gas and time to find the line at the end.

The one thing I got right - which I'd like to expand on for those who may want to learn from my challenges - is that things will wrong, with a plan, with equipment, with the dive itself, yet - Panic is not an option to be accepted. Think out the other options in advance, with study, training, practice, etc, quickly and repeatedly reivew the inventory of options in a descending order, and continue to excecute the next, seeminly best action.

Yes it's good you didn't panic.

 

[MikeFerrara]

Saying "I told you so" may be true, but it doesn't use the incident to address the problem.

Maybe, but don't you get tired of seeing divers doing the same dumb things over and over like they were the first ones to ever do it? Maybe we need plainer more to the point explainations. These these things don't just happen on their own. You have to screw up a bunch of stuff.

Just read this thread...people talking about surfacing at 500 psi and using hang tanks as backup in OW. We all know where this garbage comes from so I won't say it but taking this mentality and these swimming pool safe methods on a 120 ft wreck on the east coast is STUPID regardless of how often it's done.