DCS due to reading computer wrong (I think)

[Edward3c]

Do you not consider 1.4 to still be high? I am confused about your statement as this becoming the accepted limit as a pose to a resting decompression limit of 1.6, where is this the case?
Also why would the PPo2 effect END?

During BSAC's Diving Conference in November last year Dr Richard Pyle stated that using 1.4 rather than 1.6 was the way to go.

Its the N2 which would be 4.56Bar at 50m (on a 24% mix), whereas people get narked at 3.16Bar at 30m (on air).

Kind regards

 

[xyrandomyx]

I wasn't there, so I won't judge it. But the organization does not sound as if was safe. for example, no assigned buddy teams.

Did the divemasers have doubles?

We could have a long discussion about what practices the dive op should follow and how much responsibility they should assume for divers. It would have very little to do with diving and be more of a reflection of posters views on politics, ethics and philosophy. But, in the end, we all know that no matter how little you expect from an op, there's almost certainly one out there that doesn't meet those standards. So it's always going to be wise to look out for your own safety.

 

[Hintermann]

Did the divemasers have doubles?

Sam did not. As far as I could see, Madison, the other guide (who ascended earlier with the aforemntioned 4 Brits) did not either.

Of the first group, I did not see what Jesse was using. Kim (Mrs JJ) ascended just past me as we descended and she certainly had just one tank. But I have a feeling that she did not go down to the deck on that dive - having done the dive so many times before.

I don't think any of the divemasters dropped below 45m but it might have been an illusion. The visibility was uncanny and they could see us very clearly from where they were.

As for buddy teams, it is quite possible that the regular buddies continued to consider themselves so during this dive too. They were all diving together anyway. As I was alone, I always went with one of the guides. During the briefing JJ specified sticking together during descent and while at depth but acecpted that not all divers would want the full 15 minutes bottom time ("If you so feel, you can just touch the wreck and ascend right away but no more than 15 minutes bottom time" were his words). Sam remained with me after the others left and so in a sense he was my buddy.

While hovering above me, Sam pointed out the interesting bits on the dive - the tanks, vehicle chassis etc and we exchanged OK signals a few times. His body language at the time did not indicate that he had any concerns. I expect that he assumed that I would complete a longer safety stop when he left me at 10m. It was entirely my fault that it turned out the way it did.

 

[The Diving Badger]

During BSAC's Diving Conference in November last year Dr Richard Pyle stated that using 1.4 rather than 1.6 was the way to go.

Its the N2 which would be 4.56Bar at 50m (on a 24% mix), whereas people get narked at 3.16Bar at 30m (on air).

Kind regards

1.4 as the way to go for what? As a CC set point or working OC? A high PPO2 at the end of a week of high and prolonged exposures?

If you have time have a look at CO2 and O2 and their narcotic properties, in particular the additive effect with N2. Removing these two gasses from the equation demonstrates lack of appreciation of the whole picture.

 

[halocline]

We could have a long discussion about what practices the dive op should follow and how much responsibility they should assume for divers. It would have very little to do with diving and be more of a reflection of posters views on politics, ethics and philosophy.

Of course it would everything to do with diving! What do you think, someone's politics affects safe diving practices? How is that possible?

To me this is really very simple; all professional dive operators, meaning companies or individuals that are taking money for organizing and leading dives, providing tanks, sending guides into the water with divers, etc...have a responsibility to adhere to generally accepted safe diving practices. If what has been posted on this thread is accurate, I believe that any reasonable, informed 3rd party would easily come to the conclusion that this dive does not adhere-not by a long shot-to safe standards for recreational diving.

Legally, that's a different story, but you can bet that no dive op in U.S. jurisdiction would dare do this. They'd get creamed if someone got hurt and sued. They're apparently violating the most basic standards of safe recreational diving set by any of the recognized agencies.

And of course, I think everyone agrees that the ultimate responsibility for diving safely lies with the diver. I believe that, and I try to dive accordingly. But that doesn't release the operator from responsibility IMO. And the idea about the captain being a "bus driver"? No way...this boat is leading dives, not simply picking up passengers on a route.

 

[RJP]

But based on what you guys have said (which I fully accept), why then do they allow us to dive the SFM on single tanks? I mean why is there that arrangement at all? Of the 13 other divers on the SFM dive, at least 7 (including me) did not have tech diving experience - I know because we talked about our experiences during the course of the week. All except one were on single tanks - I do not have twin tank experience anyway. From what was said by JJ during the week, I understood that this was quite common. I tried to find an old e-mail from them where it simply said " a few of our dives are a lot deeper than 40m" and copy it here as proof but I must have deleted it.

Because there is sufficient number of divers with more money than good sense...



But seriously. There is a marketplace demand, and the Odyssey is fulfilling it. They are doing what they can to make it as safe as possible, but you are proof that there are people who will gladly pony up $2,995 to do the dive as offered. If the Odyssey only took certified tech divers to the SFM, or anything else that exceeds recreational depth/NDL, they'd be running 1/2 empty boats. And out of business in short order.

There are plenty of other wrecks on the Odyssey itinerary that can get you into the 50m or deeper range - and certainly plenty that can get you into deco pretty fast - but no one seems to make as big a deal about diving those without proper training/certification/gear/planning as they do about doing the SFM.

 

[Hintermann]

Because there is sufficient number of divers with more money than good sense...



But seriously. There is a marketplace demand, and the Odyssey is fulfilling it. They are doing what they can to make it as safe as possible, but you are proof that there are people who will gladly pony up $2,995 to do the dive as offered. If the Odyssey only took certified tech divers to the SFM, or anything else that exceeds recreational depth/NDL, they'd be running 1/2 empty boats. And out of business in short order.

There are plenty of other wrecks on the Odyssey itinerary that can get you into the 50m or deeper range - and certainly plenty that can get you into deco pretty fast - but no one seems to make as big a deal about diving those without proper training/certification/gear/planning as they do about doing the SFM.

You could be right. The problem with SFM seems to be that while just out of recreational dive depths, it is loaded with a lot of war material - the so called "million dollar wreck" reputation. I guess that makes it stand out as a special dive to all comers - I admit that I was keen to dive it as were most divers on board.

 

[Edward3c]

1.4 as the way to go for what? As a CC set point or working OC? A high PPO2 at the end of a week of high and prolonged exposures?

If you have time have a look at CO2 and O2 and their narcotic properties, in particular the additive effect with N2. Removing these two gasses from the equation demonstrates lack of appreciation of the whole picture.

I would appreciate your expert enlightenment on the effects of these gasses for the dive under discussion; 54m on a 24% mix v Air?

Kind regards

 

[DandyDon]

You could be right. The problem with SFM seems to be that while just out of recreational dive depths, it is loaded with a lot of war material - the so called "million dollar wreck" reputation. I guess that makes it stand out as a special dive to all comers - I admit that I was keen to dive it as were most divers on board.

51.4 meters = 168.6 feet. I'd call that much more than "just out of recreational dive depths." You seem resistant to calling this dive what is is: A Tech Dive, done as a Trust-Me dive on your trip.

 

[Agility]

Nitrogen, oxygen and CO2 all have narcotic properties Roles of nitrogen, oxygen, and carbon dioxide in compressed-air narcosis