What to do if you ascend too quickly?

[Cave Diver]

I *think* that the general consensus from the medical community would be to get on O2 and monitor for signs of DCS. Seek additional help as appropriate.

I'm going to amend the response I gave regarding a recreational diver within NDL's to align with this:

If the diver did not have a decompression obligation, s/he could exit the water and be observed for one hour (without the need for oxygen therapy).

Upon further reflection, I recall hearing that a diver should not be put on O2 unless they are exhibiting signs of DCS. Use of oxygen can mask or delay the onset of symptoms. Rather, they should be monitored for symptoms and if any are exhibited, then they should be placed on oxygen and seek immediate medical attention.

If they are asymptomatic and choose to go straight on to O2, then they should seek immediate medical attention to ensure they have not masked any symptoms.

 

[DCBC]

DCBC, for recreational diving, why not DAN? The question from Valhalla was "My question is who is the definitive source for such information as it relates to more experienced divers and opertations?"

I mentioned that for recreational divers it is up to the individual. DAN of course is a useful source of information. I believe this is analogous to the question "What decompression tables do I use?" Again the diver is free to choose to use the USN Tables over the DCIEM tables, for example, even though the DCIEM tables provide more safety.

DAN is one source, but not the only source for the recreational diver. When in doubt, a call to DAN would be advisable.

As I mentioned, such a situation is common among commercial divers. We too are human and susceptible to the same gas laws as everyone else. I'm not giving medical advise here, but I would do exactly what the OP described, submerge and finish my decompression profile. The USN Diving Manual and the IMCA standards agree that this would be the safest procedure as long as the diver was asymptomatic.

I thought I understood Valhalla's question: "Who is the definitive source for such information as it relates to more experienced divers and operations?" The term "definitive source" is arbitrary unless the source has responsibility and authority. That's why I answered the question in the manner that I did. The terminology exxperienced divers and operations could be clarified.

 

[waynne fowler]

In Water Recompression is a controversial procedure and I don't know that any clear benefit has been established.

I don't believe we're talking about IWR in the sense you imply.

I *think* that the general consensus from the medical community would be to get on O2 and monitor for signs of DCS. Seek additional help as appropriate.

IMO there's too much missing information to really give an answer to the OP's question.
'assuming' this was a 'recreational dive' done well within NDL's with minimal exposure prior to the event and the individual was in reasonable health and properly hydrated I'd have done just what they did.

 

[DCBC]

Upon further reflection, I recall hearing that a diver should not be put on O2 unless they are exhibiting signs of DCS. Use of oxygen can mask or delay the onset of symptoms. Rather, they should be monitored for symptoms and if any are exhibited, then they should be placed on oxygen and seek immediate medical attention...If they are asymptomatic and choose to go straight on to O2, then they should seek immediate medical attention to ensure they have not masked any symptoms.

That's correct CD, as long as the diver is asymptomatic, or until a DMO determines otherwise.

 

[holeup]

People die like that. I have seen it. In recreational and commercial.
Let me tell you one incident I saw unfold first hand that’s is very similar.
I want to reply to this thread because of that experience.
Also note I am specifically speaking of recreational. I may have done a similar move
on a work dive. But for recreational I just dont think I would recommend such a move.
At least not to 90 ft

First off, if the details of this dive profile are correct, the diver is lucky to be alive in my opinion. 2nd Re compressing in water, on one’s own is a super high risk given the circumstances here. Same tank, same gear etc. I’m not 100% sure on the year I may be off one or two so I am going to say say late 90s like 1998 but here is how it went down. I boat dive for lobster just south of Sebastian inlet to vero beach Florida no less than 20 dives a year, Sometimes more if vis is good and I also use this spot to help my buddies get in bottom time and to learn hunting skills. Offshore there is a steep lime rock ledge that drops to 80 to 90 feet. One spot in particular I use is exactly 98 feet.
It’s this area where the lobster are the biggest and most abundant. I was anchored at this site and about 50 yards south of my boat was another dive boat. I could see it clear enough to know the 1 solo diver on it was doing same as I, trying to bag his daily limit. Anyway here is what happened, and I didn’t know the full details till that evening on the news channel. I don’t have permission to us their names so I won’t. I’ll give you the details as I saw them and what happened later. I geared up as usual, went over the dive plan again with my buddy and we went over. Dropped to 82 foot I bagged two decent lobsters in one net and I never forget the look on my buddies face, he was like damn 2 4 1! The bugs we spotted after were small, under legal size, we gauged a couple more he caught and decided to surface. I had another spot in mind after a surface interval we could hit. At 25 minutes we surfaced as planned. I had set a profile for a 3 hour surface interval to do a little fishing and just enjoy the afternoon. It was just perfect.
Vis was good, current was average and just a smooth dive. When we got into the boat, my other friend
The bubble watcher said dude, look at that guys catch! We turned and the diver south of us had a bag full of bugs. I’d seen this before and wasn’t impressed. But then what happened next blew me away.
He took off his rig, put another tank on his BC and dropped over again. You had to be there to get the idea but he was in the boat no more than 5 minutes. I immediately thought, he’s diving the ledge but not going to bottom. Must be hanging around 20 or 30 feet. We went about our day. Fishing was much better further out so we pulled anchor and headed east to a spot I had on my gps great for fishing.
When we got there and dropped anchor, I was getting fishing gear together when I saw the other divers boat heading straight for shore. This caught my attention because I know shore there is hell on boats.
Once you get close the rock reef rises up in spots to less than 5 feet. You can totally destroy a boat like that. It’s also popular for shore divers, fishermen and snorkeling. Eventually we lost interest and carried on with fishing. We burned our 3 hours up and headed back toward shore south of our last dive spot.
When we got close again we could see the boat that the other diver had beached right on the shore. No idea at the time why or even how he managed to get it across the rocks and onto shore but there it was. And there were police ATVs, a crowd of people and a news crew. We got as close as we could, about 2oo yards offshore. My friend said, maybe we need to go in and tell them what we saw. We all agreed but to do this, we have to go up to the inlet, navigate into the boat ramp get the truck and drive south to the beach. We aborted our plans and headed in. When we got there only one deputy sheriff was there, near the boat and a few onlookers. We told the deputy all we had seen about the diver which really wasn’t much but we felt it was our duty. He took the info down and we asked…what happened. He told us possible drowning, but nothing else was available right now. He asked us if we knew him we said no and he told us that’s about all we know. Not a lot of info from the deputy.

Later that night we got the news from a local channel on TV and this my friends is what happened.

The solo diver was in a boat with a person who not only was not a diver but also had no boating experience. That’s not conjecture, that’s what was in the news report.

The diver went to 80ft according to the report, surfaced after 40 minutes, changed tanks and went back to 80 foot for 40 minutes. When he surfaced, he said to his companion in the boat “ I don’t feel good”
And became unconscious. The other person in the boat headed straight for land, crashing the boat on shore and yelling for help. 911 was called and the diver was pronounced dead on arrival at hospital.

My take on this incident:
At 80 foot for 40 minutes. That’s the MAX no decompression bottom time if your using the standard navy tables
10 minutes over if you use Doppler
And if computer, probably closer to 8 to 10.
He had no surface interval to speak of.

Autopsy later revealed heavy decompression sickness.

The fact that this thread says the diver surfaced rapidly from 90ft
then immediately went back to 90 feet and resurfaced normally
Should scare the hell out of anyone. Its borderline at best and by the way.
Ever since that incident between vero and Sebastian, my toolkits
contain an oxygen kit and chamber location.

 

[lowviz]

Negative. You do not need to seek medical attention if you are asymptomatic.

NetDoc:

<As this is the "Basic Scuba Discussions" forum>

Way too complex for me to agree with you on this. How long into deco, (if asymptomatic) how long since the incident, who is doing the assessment...

My take on it remains:

Seek medical attention.

 

[DCBC]

The fact that this thread says the diver surfaced rapidly from 90ft then immediately went back to 90 feet and resurfaced normally Should scare the hell out of anyone.

Hi holeup,

In this case the diver did one dive to 90 feet. This was not a repetitive dive as the surface interval was not long enough. Even so the dive was completed under NDL.

The only consideration here is that the ascent was positively buoyant (which causes concern). The diver was asymptomatic on surfacing and then went down for the purpose of fulfilling his decompression obligations (safety stop).

Obviously not all information is known in this case, but the OP was looking for some discussion on the situation. Certainly what was apparently done is sanctioned as correct procedure by the USN Diving Manual, CF Dive Operations and the IMCA D014 Code of Practice for Diving Operations.

It's hard for me to throw stones for something that I think was prudent, but like many things in-diving, it's a judgement call that's made by the diver at the time.

 

[Bubbletrubble]

Obviously not all information is known in this case, but the OP was looking for some discussion on the situation. Certainly what was apparently done is sanctioned as correct procedure by the USN Diving Manual, CF Dive Operations and the IMCA D014 Code of Practice for Diving Operations.

@DCBC: OK. Now I'm confused. Apparently "what was done" = the diver re-descended and did his various stops. Here's the source link to the USN Diving Manual that I am referencing. It states very clearly in Table 21-3 (and section 21-3.6) that in the scenario you describe (uncontrolled ascent from greater than 20 fsw with no decompression obligation and asymptomatic) that the course of action should be simply "observe at surface for one hour." There is no mention of returning to safety stop depth for extended stop time.

Do I have an outdated version of the USN Diving Manual? Or am I reading the USN Diving Manual incorrectly?

We can discuss the pros and cons of what a recreational diver should do in that scenario, but I still think it would be helpful to agree on what the USN recommendations actually are.
===========================
Edited Later: I just re-read post #31:

Assuming that decompression was required and the decompression stop was 20' or less (which was the case with a 15 foot safety stop) the U.S. Navy Diving Manual suggests that if the diver has been on the surface for less than 1 minute (which was the case) that the dive be continued. One minute is added to the decompression obligation. If the diver did not have a decompression obligation, s/he could exit the water and be observed for one hour (without the need for oxygen therapy). As the diver in this case arguably had a decompression obligation (safety stop), he did the right thing by descending to complete his profile. If he took the position that he didn't have a decompression obligation, he could have just left the water.

I think that's pretty clear. USN recommendations:
-------------------
Scenario #1: Uncontrolled ascent from greater than 20 fsw with no deco obligation and asymptomatic
Course of action: observe for one hour
-------------------
Scenario #2: Uncontrolled ascent from greater than 20 fsw with missed deco obligation at depth shallower than 20 fsw and asymptomatic
Course of action (a): with less than 1 minute surface interval: return to depth of stop and increase stop time by 1 minute
Course of action (b): with greater than 1 minute surface interval: return to depth of stop and multiply 20 fsw and 10 fsw stop times by 1.5 OR Treatment Table 5 (1A) for surface interval 1 - 5 minutes OR Treatment Table 6 (2A) for surface interval greater than 5 minutes.

Table 21-3 also sets forth the recommended course of action if the uncontrolled ascent from greater than 20 fsw with missed deco obligation at depth greater than 20 fsw. I didn't quote it here because it didn't seem relevant.

 

[holeup]

I wouldnt disagree with you here. In fact as I said had it been me I may have or may not have made a similar move. Depending on circumstances and symptoms or lack of any. One thing I was trying to hint at between the lines here is experience level. If the diver is a novice, he might panic, he may compund the problem or worse what if sysmptoms developed at depth.. i can go on and on. But on the other hand. I put myself in his fins. Had all been well, and i felt good i might simply make sure my gear was good to go and drop down and complete the dive too. It would be a call to make at the time and hard to say here. In work environment Im sure i would have been checked out,instructed to complete the dive, infact would have been given a new profile etc. But this is a rec dive and not even similar. Its a good situation to open for discussion.
Im just glad he didnt develop symptoms or embolize. Uncontrolled ascents scare the hell out me. I think most of us have had buoyancy issue at some time or another, its a whole other skill set.
Again i want to point out I am not saying there is a wrong or right move on this particular dive
except the experience level perhaps. If I were there at the time I may have sugessted he resume the dive, or been strongly against it. All depends on the details at the time.

 

[holeup]

Side note:
The rapid ascent. He had a faulty BCD? and returned to 90ft
or was having issues with the rig in some way? If he was using a faulty BCD and returned to 90ft and this happened again, im sure we would be discussing an incident here instead of this topic.