The depth shall be 60, 60 shall the depth be, 61 is right out unless your AOW certified????

[boulderjohn]

I am fairly certain that I cannot do it and that somewhere halfway up my urge to breathe will push me over to "better SWBO/AGE/DCS topside than this" ascent speed.

If you somehow do exhale all that expanding air on the way to the surface and experience an overwhelming urge to inhale, then by all means inhale. Just make sure you begin to exhale that air as you ascend.

 

[NAM001]

So the argument here for me is that the c-cards don't mean much. How can an agency or any of its affiliates recognize me as having the qualifications (CERTIFY) of diving at any depth, whether it be,

OW, where one only performs 4 checkout dives (in my case 2 of the 4 reaching a 60 ft depth) or AOW where one only has to perform 1 deep dive (mine reaching 82 ft, but now because I did this and 3 other specialty dives in 45 ft water and one specialty on the boat, I can be certified to 100 ft.)

doesn't make a lot of sense to me. The OW manual doesn't get to a point where it says, "STOP!, You may not go below 60 ft.so there is no need to know how things are different at a greater depth," but instead gives information regarding changes below that point.The AOW manual doesn't get to a point where it says, "Stop, you may not go below 100 ft," but does read, "Although 40m/130 ft has been set as the maximum, for general purposes, you probably want to treat 30m/100 ft as the optimal maximum limit....." It goes on to give 4 practical reasons you shouldn't go below 100 ft., which is the same information given in the OW manual (although in my old manual, there is no depth attached to the info.)

Did you tell your wife you were going deeper? I don't see that situation having anything to do with being certified to a depth but instead simply not having enough experience. More diving, with an explanation (dive plan) of how deep a dive will be and/or an instructor will lead to a diver becoming more comfortable. The knowledge gained in a course/book can't be dismissed obviously, but getting in the water and applying skills learned (checking spg, breath control, safety stops, checking NDL, etc...) is what, IMO, will qualify a diver to complete dives at various depths.

How, before getting an AOW certification a couple of weeks ago, was I not qualified to go below 60 ft. when I possess the same skills needed in scuba whether going to 60 ft or 100 ft and have had the experience of a large portion of my dives being below 60 ft? That is an argument that goes on quite a bit on SB.

No answers here; just spouting off!!

Yes I did tell her we were going deeper. What surprised her was that when we got there it felt no different than at 30' and as such she had no more concerns than she had at 30' It was an eye opener for her in that she was experiencing what the training TOLD her about.
The book doesn't say stop you are at 60 ft. What it does say is that you will learn the skills needed to successfully complete a dive to 60' max. They take no liability for you if you go past 60'. You want coverage to 100 take the AOW class. Granted the physical skills do not change much but the planning does. Too many newbies dive to 100 ft with 30' plannning. Too many of them call the dive with less than 500 psi when in depth just like they do at 30' Too many have shared air and have been towed back to the boat.

 

[AdivingBel]

Well, I have an upcoming charter scheduled to dive the Vandenberg where the operator has made it very clear that they expect to see AOW and Nitrox certs before I get on the boat.

I don't know which op you're using, but I have dived the Vandenberg several times. The op I used couldn't care less about Nitrox. They do want you to have an AOW or some other proof of similar diving experience. If you don't have it, they will still take you if you hire a guide that costs considerably less than an AOW and/or Nitrox cert. Again I would advise getting both certs if you are going to do a lot of vacation diving. It just makes life easier, but it's not mandatory for "one off" dives if you (the diver) are comfortable with the dives. None of this has anything to do with agency depth recommendations AFAIK. Good luck with your dives. Nothing against the dive op you've chartered. Sounds like you've done your due diligence before booking. Actually, IMHO, that's my first rule of vacation diving. Talk to the dive op in advance and know their rules. Their boat, their rules.

 

[dmaziuk]

If you somehow do exhale all that expanding air on the way to the surface and experience an overwhelming urge to inhale, then by all means inhale.

Yes, very funny. On a 25-yard horizontal breath holding swim I begin to want to inhale at about yard 24. Nowhere near overwhelming, but it's there nonetheless. I doubt that "humm"-ing out all that expanding air will vent enough CO2 to keep that urge away. I also doubt I'm going to time my "humm" exactly so that in the last 5 yards I won't have a pressure drop in my lungs sufficient to cause a blackout. I fully intend to never find out, knocking on wood, fingers crossed.

 

[boulderjohn]

Yes, very funny. On a 25-yard horizontal breath holding swim I begin to want to inhale at about yard 24. Nowhere near overwhelming, but it's there nonetheless. I doubt that "humm"-ing out all that expanding air will vent enough CO2 to keep that urge away. I also doubt I'm going to time my "humm" exactly so that in the last 5 yards I won't have a pressure drop in my lungs sufficient to cause a blackout. I fully intend to never find out, knocking on wood, fingers crossed.

The difference between the horizontal CESA in the pool and the one done vertically in real life is night and day. I recently made a post about this in the Instructor to Instructor forum in which I argued, as I have before, that the way the CESA is taught in the pool is dangerous because it teaches the students the exact wrong thing about the CESA. It teaches them that they probably can't do it in a real emergency, whereas in a real emergency it is much, much, much easier because of the expanding air. If they think they can't do it, they are likely to hold their breath, leading to a fatal embolism.

The other thing it does not teach them is exactly what you referenced in your "very funny" comment. There was nothing remotely funny about my comment. If you are doing a CESA from such a depth that you actually do exhale all you have and do feel that need, all you have to do is inhale. You will get more air from the tank because the tank was not actually empty when you started the CESA. The problem was that the regulator could not deliver air at that pressure. When you ascended to a lesser pressure, it could not give you a breath of air. We fail students in the CESA exercise if they take a breath in the last 5 feet; we should reward them for doing the right thing instead.

 

[dumpsterDiver]

For fun, I've done many ascents from about 60 feet to simulate an emergency swimming ascent.

We also were required to do one from 60 feet for our certification dive for PADI scuba diver (a long time ago). It is not that easy, particularly if you start out negative and don't move fast enough. If you are scared, or nervous or out of breath - it will not be easy.

I did mine in 40 degree quarry, with 8 ft visibility, no BC and was absolutely terrified, especially after 15 seconds of hard kicking and I looked down and was just treading water and was still 5 feet off the bottom.. I had to sprint the remaining 55 feet to "make it". I was only 13, but it was literally as scary as any roller coaster I had ever ridden.

If you are relaxed, take a few deep breaths and get neutral and then start the ascent.. 60 feet is pretty easy.

I find it amazing that certain individuals will state that a pony bottle needs to be sized so that the diver will remain on the bottom for a full minute (and breathing like a freight train) before they can initiate an ascent and this "delay" is one of the reasons why large pony bottles are being recommended - (not to mention an additional assumption that they will continue to breath like a freight train for the entire ascent). I personally think this advice is overly conservative because if I have an out of air emergency, I am getting the hell out of Dodge NOW, but if people want to make conservative assumptions, it certainly isn't dangerous to take a large pony bottle.

However, I am now seeing comments that seems to be from the entirely different end of the spectrum, telling people that a 60 ft ascent (with ZERO air) is trivial and can be done easily and the diver will not pass out. Of course it can be done - and for certain people, in certain metabolic conditions it WILL be easy, but for the average, overweight, middle aged scuba diver who is making a true emergency ascent with zero air.. it might be damn hard. Maybe so hard that they don't make it, especially if they are too negative and over-exert themselves. And if they have no ballast to ditch for the ascent, things can get out of hand very quickly as they try to swim up.

If you have a low on air ascent and can sip the expanding air from the tank, this is a HUGE crutch and will make the ascent much, much easier, but I don't think we can assume that there will always be a functioning regulator in all situations.

Practicing a true emergency swimming ascent is so DANGEROUS that it is not allowed to be taught (anymore), but people are being told that it is not hard and you wont pass out etc.. If I truly believed that "line" I would not be carrying a pony bottle on a lot of dives.

Why is a diver going to be able to calmly exhale one single breath of air on an ascent (in a CESA), but when he makes the same ascent on a pony bottle he will be on the verge of panic and will be breathing 50 times to cover the same distance?

 

[wildbill9]

Great responses, very informative. Sounds to me like it's a recommendation more than a rule. The lack of the AOW was.only questioned once. Our group of 4 divers had gone down to Ft Lauderdale we went on one dive and made mention we wanted to dive the Speigal the next day. Captain explained that you needed AOW certification to dive it. I inquired if they would wave it if we could show our dive logs showing how long, how often and how deep we are experienced at. He replied we would need to take that up with the dive master/shop owner back at shore. As we kitted up we talked about where we had dove over the last 18 months, we all have our own gear (not new but not old, it has a few battle scars), we each checked out our partner and talked about our dive plan and what to do if the unexpected occurred. We dove our plan and once we were back in to boat he informed us that he had already called the dive shop and gotten permission for us to dive the Speigal . This showed me a nice degree of professionalism, they were able to access our abilities and make a judgement call.

 

[TMHeimer]

The difference between the horizontal CESA in the pool and the one done vertically in real life is night and day. I recently made a post about this in the Instructor to Instructor forum in which I argued, as I have before, that the way the CESA is taught in the pool is dangerous because it teaches the students the exact wrong thing about the CESA. It teaches them that they probably can't do it in a real emergency, whereas in a real emergency it is much, much, much easier because of the expanding air. If they think they can't do it, they are likely to hold their breath, leading to a fatal embolism.

The other thing it does not teach them is exactly what you referenced in your "very funny" comment. There was nothing remotely funny about my comment. If you are doing a CESA from such a depth that you actually do exhale all you have and do feel that need, all you have to do is inhale. You will get more air from the tank because the tank was not actually empty when you started the CESA. The problem was that the regulator could not deliver air at that pressure. When you ascended to a lesser pressure, it could not give you a breath of air. We fail students in the CESA exercise if they take a breath in the last 5 feet; we should reward them for doing the right thing instead.

Good points. Especially about doing the right thing and inhaling if need be when getting closer to the surface. When I practise CESA from 20-30' I start with maybe lungs half full, as I have mentioned. Figuring that for some reason I was totally OOA and got zip when inhaling. About half the time I do inhale maybe 5' from the surface, the other half not. Probably could make it every time if I had to. Doing a CESA from those shallow depths, as in the OW course, with a full breath to start with is incredibly easy- To a point where you think "why bother to teach it that way cause it won't happen that way"?

 

[John C. Ratliff]

Here is a very interesting article from the Divers Alert Network (DAN), parts of which I am reproducing below:

Theory Into Practice
Emergency Ascents: Managing the Risks
...The Stats
In a recent analysis of 964 diving fatalities, we found that emergency ascents were involved in 30 percent of cases — 288 to be exact. In 189 of these emergency ascents, a rapid ascent (faster than 60 fpm) was witnessed or recorded. In 10 percent of emergency ascents, divers attempted a free ascent without using a breathing gas supply. Buddy breathing was involved in 8 percent of fatal emergency ascents. In the remaining cases, the mode of emergency ascent was not specified.

The most frequent trigger of an emergency ascent is running out of breathing gas during the dive, an entirely preventable cause. For more on this topic, see "Theory Into Practice: Out-of-Air Emergencies Don't Have to Happen," in the July/August 2009 issue of Alert Diver.

The most common cause of death in fatal emergency ascents is arterial gas embolism (AGE), accounting for 54 percent of cases, followed by drowning at 18 percent, acute cardiac events at 7 percent and decompression sickness at 5 percent. AGE is a stroke-like condition with sudden onset of weakness and unconsciousness that usually occurs within minutes of surfacing. It often renders a diver unconscious before he gets out of the water or soon after...

...

SeaRat

 

[boulderjohn]

Here is a very interesting article from the Divers Alert Network (DAN), parts of which I am reproducing below:

While the article is generally good, there is one very glaring problem in it that really raises questions about its authorship. It says, "Keep your regulator in your mouth at all times; sometimes air expands and gives you one more quick breath."

Yes, you should keep your regulator in your mouth for two reasons, neither of which has anything to do with expanding air.

1. If you do involuntarily inhale while ascending with the regulator in your mouth, the worst that can happen to you is that nothing will happen. The best is that you will get some air, as it says. If you ascend with the regulator out of your mouth and involuntarily inhale, the drowning process will begin immediately thereafter, and that is not good.
2. If you have ascended far enough, you will indeed get a breath of air, maybe more. The air in your tank did not, however, expand, as the article says it does. Gas inside an inflexible container does not react to outside pressure. The regulator is designed to deliver air above ambient pressure. If the pressure in the tank gets too low, it can't do that. As you ascend, ambient pressure (the pressure of the water around you) decreases, and when it decreases enough, the amount of pressure still in the tank will be enough to allow the regulator to give you air.

It is actually a little scary to me that the person who wrote that article did not know that.