Bent in Belize--Blue Hole Incident

[Mike]

I do not believe the op should have done the dive and then started using another computer, but using your logic anyone that did dive the Blue Hole and is not tech trained should not dive anymore either. That would be a lot of people.

I think by the op posting this may make people think twice before exceeding their training for a dive like this.

Please re-read his original post. I think there was some deco diving in there and even some deco diving without a computer with some guess work involved, and even still a bit more than that.

Like I said, I don't want to beat the guy up but there is probably no way to not come across as doing so.

 

[rjk75]

What you just wrote is exactly the reasons why I agree that you should probably not dive anymore.

...snip... snip...

but my advice would be to stop diving until you reach a lifesaving epiphany about how out of control your diving has become, some reflection looking back at just when did you take the divergent path, self-analyze through you log book until you come to a realization of at some point you started diving without a fear of self-preservation.

Mike, very well said--you are so right-on! He was bucking for the Darwin Award.

 

[Rooster In Ohio]

Okay, I've actually read the whole string. Thoughts and questions:

1. I presume from several stray comments that the OP is an AOW diver with 50-100 cold, drysuit dives, has been deep at least a few times, knows his equipment and brought his own equipment because he planned to go deep this trip. Analysis: the dive begins upon deciding to dive - in this case, back in Canada and with the foreknowledge that a Blue Hole dive would be at least 130FSW [if not more]. OP takes some appropriate steps, including the decision to schlep his own gear with him.

2. The diver decided to dive solo with limited / non-redundant gas. Analysis: The diver knew that it is doctrine/best practice, ESPECIALLY given no gas redundancy, to be paired with a buddy and even vocalized it to the DM but accepted the DM's decision to dive as a group. Question - what prevented him from looking around the group, sizing someone up that looked to be of similar experience, and buddying up?

3. The diver decided to dive beyond the maximum recreational limits. Analysis: It is not clear WHEN the OP made this decision but it would be safe to guess it was not somewhere between 100 and 130FSW. It may be that the diver was sufficiently comfortable with his age and fitness and made a conscious decision to dive the Navy tables, maintained a bottom time of 5 minutes (we don't know this from his narrative), and ascended directly such that the dive was actually a NDL dive (by that table) notwithstanding the fact that his computer (which almost certainly is more conservative) showed a deco oblication.

4. Notwithstanding 1-3, the diver returned to the surface with no deco obligation. At this point and ignoring for the moment the several complete lapses in judgment that followed, I have to ask a question: Should anyone sitting in their home that decides to book a trip and dive blue hole after reading this thread immediately cut up his or her c card? I get the strong impression that an AL80 dive to 150FSW is the M.O. for all Blue Hole dives (permitting the possibility of diving with a buddy and the possibility that you carried a pony with you in your travels, however unlikely) - does that really mean that no recreational diver should ever make this dive, or is it more accurate to say that this is an extremely aggressive dive that exceeds the recreational dive planner but can be PLANNED and EXECUTED with the understanding that the diver is putting himself or herself toward the ragged edge of the risk bubble? I seem to recall that one poster said he and his buddy did the dive and returned with half of their gas. Presuming 3 minutes descent, 5 minutes BT at 150FSW, two minutes to 70FSW for a one minute deep stop, and two minutes to 15 feet for your final stop, you have a run time of 13 minutes to your final stop. With a SAC rate of .75, back of the napkin would seem to put a diver at 1500psi upon reaching 15FSW and leave more than enought gas to hang for 15 minutes or longer. Again - it does not appear that the OP PLANNED but just followed - but does that mean that any recreational diver that decides to dive Blue Hole should just pack it in? Serious question looking for serious answers.

5. Diver loses his computer but has the oppotunity to make another dive with a borrowed computer. Analysis - a huge assumption of risk if the computer had been on the arm of someone you stuck right next to the entire prior dive - an astronomical one in any other circumstance, topping out if it sat out the prior dive entirely. QUESTION, HOWEVER: If the diver had PLANNED and EXECUTED his prior dive such that he knew his residual nitrogen load, he could have wipped out whatever tables he used for his first dive (Navy), planned his second dive, and used the computer in guage mode, right?

6. Diver takes a third dive with no computer and no depth guage. Analysis - I just don't know what to say about that.

 

[kendallpg]

Okay, I've actually read the whole thing and it seems to boil down to this (with some assumptions):

1.

Rooster... I believe you summed it up quite well.

 

[Duke Dive Medicine]

Thank you for the response. Do you know if there have been any studies relating onset of DCS to dehydration or insufficient caloric intake (in addition to the time/depth factors)?

I'm asking simply because DCS is the kind of thing you want to avert from every possible angle.

[h=1]Dehydration effects on the risk of severe decompression sickness in a swine model.[/h]Dehydration effects on the risk of s... [Aviat Space Environ Med. 2006] - PubMed - NCBI

This study shows an increased incidence of severe DCS in dehydrated pigs vs. normal pigs when rapidly decompressed from saturation. People aren't pigs, and most divers don't rapidly decompress from saturation, but the study authors had to ensure that there would be a high enough incidence of severe DCS to compare dehydrated vs. hydrated.

[h=1]Venous gas emboli in normal and dehydrated rats following decompression from a saturation dive.[/h]Venous gas emboli in normal and dehy... [Aviat Space Environ Med. 2008] - PubMed - NCBI

This study shows no change in the number of venous gas emboli in dehydrated rats vs. normal rats. Venous gas emboli are often used as a measure of decompression stress. Same rationale for rapid decompression from saturation.

A study done on French military divers:
[h=1]Preventive effect of pre-dive hydration on bubble formation in divers.[/h]Preventive effect of pre-dive hydration on b... [Br J Sports Med. 2009] - PubMed - NCBI

Divers who hydrated with a hyperosmotic beverage before diving had fewer venous gas emboli after diving as compared to divers who did not hydrate.

Divers often blame dehydration for unexplained DCS, but personal perception of hydration level is a poor indicator because it's very subjective. Also, DCS itself can cause significant dehydration. If lab results in a diver with DCS indicate dehydration, it's difficult to tell whether it came before or after the decompression sickness.

To my knowledge, there is no published research on nutritional status and risk for DCS.

Hope this helps.

Best regards,
DDM

 

[ktomlinson]

I'm glad that you are going to be ok. I think it's interesting that many posters have focused on the 150' dive. That dive wasn't the best decision you could have made, but the second and third dive take the cake. It was asked, but I never saw a response, was the computer that you used on the second dive used by anyone on the first dive? I don't think you need to quit diving, but if these decisions are unlike decisions you normally make, I would be careful in all aspects of life until you are really over the divorce. Our minds are interesting and complex things, it seems you rally learned something about yourself with this experience.

 

[TechDeep]

I think the OP was trying to give us some insight into the mindset that led him to make such poor decisions, and I think it is constructive. I doubt the repetitive scolding is, but who knows, maybe he missed all the others. I would guess that most people who get bent do so not out of ignorance of prudent practice, but rather some variation of the OP's thought process.

Was just an observation, and an attempt to be helpul, simple as that. Not inteded to be scolding in any way.

 

[mrfixitchapman]

I've dived from a boat with some real jerks aboard, but this thread convinces me not to dive with swine. Even if they are hydrated.

DC

 

[scubadada]

Very interesting, long thread. So what would you do?

If I went to Belize, I would most certainly take the opportunity to dive the Blue Hole. I would dive to 150 feet with an Al 80. The 8 minutes of NDL would cost me less than 20 cu ft of air. I would avoid deco or have not longer than 3-5 minutes at 10 ft. My primary computer is AI, my backup computer runs the same algorithm. I carry an SPG if my primary computer craps out. I have DAN insurance.

Is this risky?, sure it is. I also have 650 dives with more than 150 over 100 feet. Accepting risk is a diificult personal decision. Being honest is not that easy either.

Good diving, Craig

 

[Mike]

We are going to Belize as our next dive destination and will almost positively end up at the blue hole. Will I dive it to 150 ft? Maybe, maybe not. If I do it will be with my 10 year long dive buddy who we're both rescue divers, have done deep dives together before, I'll have a competent dive buddy who I already know how they will dive and know their dive history, I'll have back up air right next to me and vise versa, we won't dive into deco. But never in million years would I dive to 150 ft with an instant buddy and especially never in a billion years with no buddy, relying on the DM. So that said I think the dive is a calculated risk to 150 ft, with the right prep, plan and dive buddy and having training and experience I think the risks can be mitigated. But take away any of the following - the right buddy, no plan, no experience, no training and I think it's way too risky a dive.