To Blue Hole or not Blue Hole...

[krunchy]

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?

Thanks, I appreciate the input and these were my concerns as well. I have no real interest in going beyond 135, at least at this stage in my dive career. I personally don't have a problem doing this on a single tank, as long as my buddy is (very) reliable.

Or I might just buy a redundant air source since I've been itching to get one for awhile.

 

[peterbj7]

Oh, man, I have a problem with this You don't have to do it then.

You're going to 150 feet on a single tank Maybe only 130ft, your choice, diving as a group, with nobody in that group tasked with staying close to you and being available if you need help Not so - there are several divemasters and they will be close by and looking out for anyone with a problem? Does anybody in the group carry enough gas to get two stressed divers to the surface from 150 feet? Yes, ample - I've done it Are you depending on the DM, who is helping the lady who is hopelessly narced, to donate gas to you if you need it Yes, but most divers don't need more air?

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. Your prerogative - many people do it without any problem and enjoy it

Apparently the software in this site won't accept all input in a quote from someone else.....

 

[TSandM]

Well, peterb7, this is just an example of how different people assess risk and decide their own limits differently. I find the dive, as described, to be a very bad idea. Obviously, a lot of people do it and get away with it.

I didn't do Devil's Throat in Cozumel, either. I just find there are lots of dives out there for me to do that don't push my personal limits of risk.

If you want to see stalactites and stalagmites, do it at 20 feet in the Riviera Maya cenotes. JMHO.

 

[njcfm]

extra tanks are everywhere at the safety stop

Dms have 8-10ft cords on their emergency regulator

we had a group of 8 people, everyone was buddied up (my buddy is my fiancee' i have trusted my life to her many, many times), and there were 2 DMs with our group one in front, one in back. There was also an extra DM at the safety stop.

Amigos Del Mar was very professional and they eased anyone's fears on the depth of the dive. I felt safe the entire time, it was all about remaining calm and thinking clearly. If you haven't had a feeling similar to narcosis (being high/drunk/etc) then i can understand your fear, but most people have had a similar feeling more than once in their life and can manage it.

 

[stargost]

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.

I was really expecting some of the usual suspects to make that comment.

We are very likely going to Belize, and I will not do the BH. The main reason being indeed because I dont want to do such a dive without a buddy I know. As the rest of the family cannot do it, I wont take a chance.
We'll come back later when every one will have more experience to make it, relying only on ourselves.

For sure the dive operators are experienced, they do that dive all the time succesfully, etc ... They have plenty of tanks, etc ...
But being new to diving, I have already seen 'experienced' DM (the best, they had CMAS card... ) very close to some bad outcomes. And we were not that deep. 1 DM, even with excellent SAC, a H-valve and 3 octos cannot take care of more than 2 persons at a time, especially if divers are not staying close to each other (which all youtube videos of the BH make pretty obvious). And expecting that an unknown diver in your group, partially narced, is going to help you in the very unlikely case you have a problem (even not air conso, but like equipment, narco, ...) is just playing too much.

We will enjoy all the other beauties of diving that are very well described here and come back later, because yes, the BH is likely a dive worth checking in your list, just for the record and what it means in the scuba history (Cousteau and so on), even if plenty of others are much better.

 

[Gaz]

With regards to diving the Blue Hole it really boils down to someones comfort in the water and previous experience and if they are comfrotable in the water.

If you dont feel comfortable it easy dont dive it however if you feel comfortable in your own abilities then go for it

As for exceeding recreational dive limits just from a liability standpoint I have to advise to stay within them. The Blue Hole can be hit and miss where viz is concerned and I wrote a short article because it comes up so often whether divers should dive it or not, not necessairly the safety side of it more the reccomendation to dive or not to dive it

Heres the link

Blue Hole Is it Worth it

Gaz Cooper

 

[stargost]

Thanks Gaz,
good article indeed, as all the rest described on your website, there are already so many dive sites to explore, it is difficult to fit all into a too short 2 weeks vacations (short is for European standard, lol !).
So skipping the BH is an easy decision eventually. Main probem remains how to change the full moon date so it gets extanded after the 4th of July to see Whale Sharks within Placencia ...

Difficult to get it all. Maybe the solution would be to trap a couple of whale sharks in the BH, (kidding...)

 

[peterbj7]

No-one's wrong here. As Gaz says, if you're not comfortable doing it, then don't do it. Every dive is (potentially) dangerous, and if enough goes wrong you can die on any dive, however shallow. It's a question of probabilities. There is no sharp distinction between "safe" and "unsafe" - it's a grey scale and all a question of degree.

I used to teach technical diving (and I may yet again) and in a prospective student I look for a fine balance between confidence and caution. Too far either way and I won't teach that person. I look for a spirit of independence - whenever people say to me that they will only dive with a buddy my reply is "why do you want the added responsibility of someone you may have to help?".

From a very early stage in my diving I stopped regarding a buddy as a potential saviour, as there are enough bad divers out there and I wouldn't want any one of them near me, and more as a responsibility and potential liability. Of course, that implies you need to carry some redundant gear with you, though even there it is just a grey scale - you can't possibly carry enough gear to guarantee nothing will go seriously wrong.

The way this dive is conducted there are sufficient well trained people near you to be able to handle any of the more likely emergencies, and probably some of the less likely ones. They will do all they can to keep you safe, and in recent years they have had a 100% success record (there hasn't been a diving-related accident in the Blue Hole for at least eight years). But there are no certainties, and if that is what you seek you'd better choose another sport.

Whale sharks are occasionally seen in other parts of Belize. I photographed one just off San Pedro a couple of years ago.

 

[TSandM]

What tanks are dived there? What do the guides have?

Rock bottom for 140 feet, assuming you aren't under a decompression obligation (which means 5 minutes or less at that depth): 5.2 ATA x 2 cf/min (two stressed divers) x 1 minute to establish the air share, get hold of one another, and begin the ascent: 10 cf.

30 fpm ascent = 4.6 minutes on ascent, assuming no safety stop (a poor decision from 140 feet, I think) x 2 cfm x average depth of 70 feet = 3 ATA = approx 28 cf. 38 cf is half of an Al80. So you need to be headed up by the time you reach 1500 psi, to have any hope of having enough gas to get two people to the surface -- and notice, there is no reserve built into these calculations, so if you follow them, your tank will be dead empty by the time you reach the great gas tank in the sky. If you are at all delayed at depth by someone who is panicky or disorganized, or if your ascent is too slow, you will have two people out of gas on the way up. If you have spent any time at depth, and you need that rapid an ascent, you might have two people on the surface with the bends.

Mike Ferrara, a SB member I profoundly respect, simply observed that there is nothing at all wrong with doing such dives. One should simply plan and excute them as proper stage decompression dives, with the appropriate equipment, gases and training. I'm quite sure the Blue Hole is gorgeous. If I ever dive it, it will be a trimix dive, and I'll have time at depth to admire my surroundings, and enough gas to get me and my team to the surface safely, no matter what happens. It's just good planning. Enough risk is enough.

 

[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.