To Blue Hole or not Blue Hole...

[peterbj7]

I, and most DMs who marshall these BH dives, usually surface with 1800-2000psi still in my 80cu.ft. tank. Yes, I have known people run out of air whilst at the bottom (of the dive, not the Hole!) and on one occasion when I took such a person to the surface I was astonished at how fast she drained my tank. But even so I had over 1000psi when we reached the hang tanks, and throughout the early part of our ascent there was a DM close by.

I think you and I exemplify opposite ends of the "caution" spread. I have done a number of deep dives (below 200ft) there by myself, albeit with adequate bail-out gas (trimix). I generally feel happier when I am solo diving, though on the occasions when I've gone below 300ft (including to the bottom) I wasn't alone. But then most of the people I dived with regularly in the UK solo dived, and I'm pretty used to it.

 

[DCBC]

I think it's safe to say that I'm one of the strongest supporters of deep air on SB. That said, any diver that exceeds the 130' recreational depth limitation should first possess additional training and experience. To do otherwise is foolhardy.

I don't care what anyone says, how many times it has been successfully done, or how many extra tanks are available. In NO way is it a good idea for inexperienced vacation divers to do a group dive to 150'. If someone gets hurt, I hope the court's judgement is substantial enough to put that company out of business permanently. It's just irresponsible.

 

[Downing]

Oh, man, I have a problem with this.

You're going to 150 feet on a single tank, diving as a group, with nobody in that group tasked with staying close to you and being available if you need help? Does anybody in the group carry enough gas to get two stressed divers to the surface from 150 feet? Are you depending on the DM, who is helping the lady who is hopelessly narced, to donate gas to you if you need it?

I would not ever do such a dive as an ill-defined group, and I wouldn't do it with an instabuddy, either, and I wouldn't go to 150 feet on a single tank, even in the tropics.

Ouch. I don't want to pick a fight here as I respect your decision but it seems to me that you exaggerate the risk--at least in my limited two-dive BH experience--in order to make your point.

In my case, we went to 130 feet, not 150, although in truth I think I got down to about 138 when I swam around one of the stalactites. Pursuant to our dive brief, everyone in my group of 8 or so divers, including two DMs and an instructor, was tasked with staying reasonably close together and available for each other, my quick swim around the rock notwithstanding. If someone(s) needed help, I'm sure at least one if not all three of the dive professionals would have been adequate to address the situation. If it's a gas issue, you didn't have to make it to the surface; you had to make it to the tanks hanging on the line at 15 feet pursuant to deep diving protocol.

In our case, we descended to the lip at 50 feet, made sure everyone was good to go, dropped quickly to 130, looked at rocks and sharks for five minutes during which the DMs personally monitored our air, then we ascended back to the lip where they again checked our air, hung out for a few more minutes watching the sharks watching us watching them, did the SS and exited the water.

Is it safe? It's at least as safe if not safer than diving a cenote. It's certainly not reckless and it's not at all like you described it.

Btw, I love diving cenotes and am pretty sure I found God in one, but there's a lot more to diving a cenote and thus a lot more that could go wrong there than there is to the quick in/down/up/out experience of the BH rec dive. No buoyancy, light or direction issues. Just down and up.

I agree that if you want to do the BH right, you really should do a trimix dive and spend some quality time down there.

As Peter said, no right or wrong answers. Peace.

 

[peterbj7]

If I ever dive it, it will be a trimix dive

What is the maximum pN2 you're prepared to dive with? Or if you prefer, what is your preferred maximum EAD?

 

[TSandM]

It all boils down to risk assessment. Every time we go underwater, we accept some risk. The deeper we go, the greater the risks are, just because it's a lot longer trip to the surface, and nobody can breathe water.

My big issue with dives like this one is that I strongly suspect that many of the people who do them have never thought through the possible problems that could occur at depth, or how they would be handled. For example, the concept of the total amount of gas required to get two people up from 130 (or deeper) isn't taught anywhere in the PADI recreational curriculum. In addition, it is my personal opinion that diving as an ill-defined group is a recipe for NOBODY being ready to handle a problem before it spirals into a real emergency. And narcosis is real, and a very possible cause of lack of diligent gas monitoring.

I know that in practice, this dive is done again and again with no issues, and undoubtedly, that's due to eagle-eyed guides who have learned how to watch and what to watch for. But that doesn't mean the dive is a good idea, and I think people reading about it should at least reflect on more than whether five minutes at depth is worth what, a two hour boat ride?

Edited to add: I use a 100 foot END, from personal experience with narcosis.

 

[krunchy]

Really? Trimix to go to 135 feet? I'm certified for Nitrox but using Trimix seems overkill to me.

Although I am enjoying the lively debate on the subject

 

[BrianOrange]

I will have the opportunity to dive the Blue Hole in two months. Right now I will not dive it. I am much too inexperienced (by the time of the BH dive I'd probably have less than 20 dives in my log book) and I think it's just too deep for me. I will pass.

All that said, I'd possibly reconsider if I could cap my dive at say 90 feet or so. Is it worth doing the Blue Hole if you only go to 90? Is this ever an option?

 

[peterbj7]

I think it's safe to say that I'm one of the strongest supporters of deep air on SB. That said, any diver that exceeds the 130' recreational depth limitation should first possess additional training and experience. To do otherwise is foolhardy.

I don't care what anyone says, how many times it has been successfully done, or how many extra tanks are available. In NO way is it a good idea for inexperienced vacation divers to do a group dive to 150'. If someone gets hurt, I hope the court's judgement is substantial enough to put that company out of business permanently. It's just irresponsible.

Fair comment, but the 150ft here is the depth of the shelf above which are the stalagmites and columns. Most people don't quite reach that depth as they would have to stand out away from the wall level with the shelf and the DMs discourage that. So their max is typically 140ft-145ft, and it's common for people to stay a bit above that. I think that in this case the excess over 130ft is a bit of a red herring. In any case, it's only for a brief while.

More to the point is that this dive is commonly performed by people with no training beyond Open Water, and often with little further experience. Which is why I said up-front that customarily I deter divers from doing the dive. However, I can't stop them so I do all I can to ensure that the dive is safe for them. Deep diving experience over a bottom is by far the best training, and I offer that. I can't compel it though. And I don't run these BH trips myself - never have.

I also don't like that many customer divers, and indeed some of the staff, aren't properly equipped with computers or digital depth gauges. Several years ago (I don't believe it happens now as procedures have been tightened up) I was on a dive there and I think I was the only person on the boat with a computer (I had two). Certainly the lead DM just had an analogue depth gauge and a watch. All the customer divers were (I presume) certified divers yet not one appeared to have any concern over this. They believed they had been to 130ft because that was what they were told and they had no means of verifying it, but I saw several - most - go below that depth to 140ft-150ft.

This gets right back to the root of dive training nowadays - it's too easy, too approachable, and people aren't thinking for themselves. Although I personally find some of the posters here unduly cautious (maybe they have been mislead by the information supplied here, given that they haven't been there for themselves), I applaud those people for thinking through the issues for themselves. Too many are just lead by the nose.

 

[Gaz]

Hi Brian

No at 90ft there is nothing to see just a sheer wall with nothign much on it, top of the overhang starts at 100ft you can easily stick to the limits and see what you came to see but many divers exceed that on purpose or not.

Gaz Cooper

 

[Web Monkey]

Hi all,
I am traveling to Belize in a few weeks and am undecided about diving the Blue Hole. Its a pretty deep dive and I'll be traveling solo. I often get paired with the DC in these cases. But I've had some insta-buddies that I would NOT feel comfortable diving the hole with, so I'm a bit torn over whether or not I should take the trip.

You should have an awesome time assuming that nothing goes wrong.

If something does go wrong, you'll discover that you don't have enough gas to make a safe ascent while doing an air-share, and unless you get really lucky, nobody else does either.

Also, as you descend, you'll get stupider due to narcosis, while at the same time you'll be over an essentially bottomless hole with no specific buddy. And since narcosis increases with depth, if you go deep enough, you'll be too narced to figure out that you should come up, and won't know how to do it anyway.

If you manage to exceed your bottom time (just a couple of minutes at that depth), you'll have a decompression obligation that you can't safely blow off, but won't have enough gas to handle, which gives you a choice between drowning, being bent or drowning someone else by sharing air on your stop.

It sounds like a really cool dive with the right gas, the right equipment and the right training, but not as a member of a "group" (essentially a solo diver) with a single 80.

Terry