Emergency Surface from 250 FT and reascent procedures

[Akimbo]

Tech divers don't like hearing this, but dives like this without a chamber on site is foolish at best, even if you are surface supplied. Regardless of expertise or preparation, you can easily get seriously bent even when the dive is executed flawlessly. We all take calculated risks so diving the Doria without a treatment chamber and people onboard that can operate it is accepting that you will die or be crippled if you needed one.

Yes, I have been there and yes, there was a double-lock onboard. Oh, and yes we used it. Everyone came home exhausted but fine.

 

[DCBC]

We all take calculated risks so diving the Doria without a treatment chamber aboard with people that can operate it is accepting that you will die or be crippled if you needed one.

Akimbo, I don't know about you, but every time I've been saturated I haven't been too optimistic about my chance of survival if an accident occurred. We all take risk daily; its part of life. If I had to have a chamber every time I did a deep recreational dive, I'd be hard pressed to dive at all...

 

[Akimbo]

... If I had to have a chamber every time I did a deep recreational dive, I'd be hard pressed to dive at all...

As you know, the Doria isn't just a deep recreational dive. Because the probability of a serious DCS incident increases with depth, time, and stress the time to treatment needs to be an inverse relationship. Then factor in the probability of conditions-induced dive plan failures.

We all make a risk calculus just crossing the street. Everyone concludes that we are dead if enough things go wrong. The trouble is that very little has to go wrong 200 miles out of New York in 240' of water to require a chamber in order to walk again.

A chamber wouldn't help at all if one of the container carriers runs your boat over even if nobody gets over the side (The Doria lies in the separation zone between the east and westbound shipping channels of New York -- a factor that didn't protect the Andrea Doria and Stockholm). We had to dodge a few even in clear weather with Coast Guard radio bulletins. We all make decisions and accept the consequences.

There was a company that tried to put a dive boat together with a chamber onboard for the northeast market, but the deal fell through. I would have gone back in a minute. Maybe after the recession is over?

To be honest, I always felt safer in sat than most dives.

 

[TSandM]

I don't necessarily think the answer is a chamber for all such dives, but I think Akimbo is right. If you make a major mistake on such a dive, you are likely to end up dead or permanently disabled, and you need to have thought about that before undertaking the dive. You need two things -- training and experience to avoid making a major mistake, and the conviction (whether any of us approve it or not) that what you are proposing to do is worth the risk you are taking by doing it.

I spend as much time as I can under overhead environments. Any of them could kill me. I remain blithely convinced that I have enough training and experience to avoid making the mistakes that are likely to do that, so the risk-benefit ratio pencils out for me. Who knows if I'm right -- but at least I've thought about it.

 

[Akimbo]

I must admonish both DCBC and TSandM for not supporting my lobbying effort to get a larger dive boat with a chamber for the northeast diving community.

Get with the program will ya! Say after me "MUST HAVE CHAMBER". Of course a moonpool and dynamic positioning would be nice.

 

[DCBC]

Any diver who "hasn't thought about it" shouldn't be doing the dive in the first-place. Obviously a chamber that's available on every deep dive is the ideal, however we don't live in an "ideal world" (yet). Diving is what it is. Diving the Doria has been only for the very experienced deep wreck divers, but like Everest I'm sure it will eventually be used for an openwater checkout.

As I mentioned, I did it on air in the 70's, as a member of a Navy dive team from Canada and the U.S. At that time, the port side of the Doria was in approx. 160 FSW. We did a limited penetration dive on the 230 foot table.

As you may have guessed, I'm from an older generation. We just didn't have the facilities and equipment that we have today. We had to do with what we had. Training was over the top in an effort to give us an edge. Today it's different. I actually do understand. I'm sure today's diver will talk of the old days, while 40 years from now every diver will have an environmental chamber in his dive bag, in case of emergency. They will not believe how anyone could dive with mix instead of a new liquid breathing apparatus that everyone will use at that time. The old timers will be criticized for using mix and branded as "dangerous and fool-hardy." Such is the life of a pioneer....

But from my viewpoint, something is lost. It was the danger and excitement that drew me to wanting to explore the underwater world; the unknown. We did with physical ability what is done with technology today. Certainly things are safer today, but that's not the most important factor to everyone. Something has been lost and in other ways, something has been gained. Obese non-swimmers in poor condition can now use mix in 300 FSW. To quote James Bond, the World is not enough...

 

[Jerrod]

Thanks for the comments. By googling In water recompression, I found multiple articles detailing out how it is handled. Including examples.

 

[Doppler]

Thanks for the comments. By googling In water recompression, I found multiple articles detailing out how it is handled. Including examples.

I have something about it in my blog... And writing a chapter about it now for a new book.

 

[Bombay High]

Yes, I have been there and yes, there was a double-lock onboard. Oh, and yes we used it. Everyone came home exhausted but fine.

At some point you've got to write about that episode. I have only read 3rd hand reports, and some stuff on the internet that a friend sent me a link to. I think it would make a great book.

---------- Post Merged at 05:45 PM ---------- Previous Post was at 05:41 PM ----------

To be honest, I always felt safer in sat than most dives.

Except when the vessel is being rocked in state 5 seas and they start sending spare scrubber thru the hatch and unbolting the chamber from the deck. I remember thinking that the last thing I was going to see was these 3 guys and the inside of the chamber.

 

[Akimbo]

I don't want to leave the impression that I don't support the concept of in-water DCS treatment under any conditions. There are situations where it is the lesser of evils. Red text added to the quote below for clarity to this discussion

You are describing a situation where you must choose what sucks the least. What preparation and skills are available, how far is a chamber, and what are the symptoms?

Oxygen for decompression onboard, 500 miles from the nearest chamber or chopper to get you there, competent safety divers, and a mild joint pain (and calm waters)? I'd be in the water sucking from the green bottle. Five miles offshore, CNS (Central Nervous System) hit, inbound Coast Guard chopper, 20 miles from a hyperbaric hospital unit, onboard a typical sport diving half-day boat? I'd be lying down on deck patiently breathing Oxygen.

The problem is the huge variability between the two circumstances described above. DAN's recommendation is likely the least of the evils in most cases in the recreational setting. However, when you are the one at risk, I believe it is prudent to know more than memorizing a general recommendation rather than interpret it as a rule from God.

I know a commercial diver and supervisor who treated himself in a chamber at the shop (no names, OSHA would have a cow). Should he have waited for help to arrive? Knowing his skill level and knowledge of the systems, IMHO probably not. My answer would be probably yes of it were most of the divers that worked for the same company. He knew another supervisor was on the way and he had been hit in the same knee before. Was it good, no. Did it suck less than waiting 45 minutes? In this case, probably yes.

Short of staying above 30', there is no guarantee any of us will never get hit, but you can dramatically decrease your risk by being conservative when choosing your dive profile. Even if you are not 100% successful with this strategy, the severity of the symptoms are likely to be far less.

Unfortunately, the type of DCS symptoms you are likely to experience on the Doria are not likely to be reasonable to treat in the water. Nor are the sea-state conditions you are likely to encounter for more than a few hours at a time. Just doing normal in-water decompression stops hanging off a moored vessel can be very challenging.

There were a lot of Scuba dives on our project to position the habitat and support us. The vast majority of water stops were hanging from a drifting Boston Whaler with O2 bottles in the keel. They would tie to the downline buoy with an O2 hose hanging at 20' waiting for divers. They would release from the buoy and drift as soon as they got the signal from the divers -- often more than a mile. The support vessel followed us so we could transfer to the chamber to complete decompression (Surface Decompression using Oxygen or Sur-D-O2)

Until we implemented this technique, divers would wave in the current like flags in a gale. It dramatically increased conditions we could operate in.

---------- Post Merged at 09:05 AM ---------- Previous Post was at 08:53 AM ----------

...Except when the vessel is being rocked in state 5 seas and they start sending spare scrubber thru the hatch and unbolting the chamber from the deck. I remember thinking that the last thing I was going to see was these 3 guys and the inside of the chamber.

Well yea, there is that. Revise that to:

...To be honest, I almost always felt safer in sat than most dives.