Weekful of OOA in Coz.

[midwayman]

My trip to Cozumel in March shook up my confidence a little bit. In my week of diving there, I saw 3 separate OOA incidents, and a couple other things that worried me.

The first was a night dive off the international pier, the last dive of my AOW cert. After zerging around the pilings, and killing 5 lionfish, we were on the way back in shallow ~10-15ft water when I notice my fellow classmate on the surface. I figured he just had buoyancy issues in the shallow water. We get out and found out he ran OOA and that's why he was on the surface. Luckily we were shallow and probably had already done a safety stop by the time he went up.

2nd was a trip to Punta Sur. We had discussed diving the Cathedral there, but several of us were uncomfortable with devil throat. We get in and have to go down super quick, and I'm having trouble clearing that fast. Eventually we get down and through the Cathedral, and our divemaster decides to take us through the devil's throat anyways. 4/6 of us come out the other side and we're hanging out at 120 while the divemaster goes looking for the other two. Eventually found they surfaced rather than go through. Shortly after that, one of the guys goes OOA and has to buddy breathe with the divemaster on the way to the surface. Get up, and he says he had a panic attack down there at 120, and one of the people who came up early had a bad nosebleed. Just a disaster of a dive.

Last one was the next dive. It was nice and shallow, and my wife starts up early and I follow her up. She grabs my octo and starts buddy breathing at the safety stop. I find out up top she kept trying to tell the divemaster she was getting low, and eventually went up on her own. She wasn't completely out at the safety stop, but well into the red zone.

Nobody really got hurt that I know of, but all of this was a confidence shaker. I don't want to see anyone have to do this stuff, let alone so much in one week.

 

[warmwaterturner]

Ultimately, as I am sure you would agree - all divers are responsible for their own safety. It sounds like a lot of people were not monitoring their gas consumption very well. It also sounds like a lack of communication and agreement on the second dive at Cathedral as to how the dive was to progress. Shallow water or not - OOA happens when a diver is not paying attention in most occasions.

 

[Crush]

It seems like there are many threads on SB that describe OOA or near-OOA situations where the divers were monitoring their air consumption, indicated to the DM that they were getting below their turn pressure, and the DM carried on with the dive so that everyone could max out their dive time. In many cases the divers who are below their turn pressure succumb to peer pressure and stay with the group instead of abandoning the dive (with their buddy). We teach kids to not succumb to peer pressure and "just say No to drugs." We should teach new divers in no uncertain terms to "just say No to OOA" and "just say No to trust-me dives."

 

[Bubbletrubble]

Thanks for sharing your story, midwayman.

The first was a night dive off the international pier, the last dive of my AOW cert. After zerging around the pilings, and killing 5 lionfish, we were on the way back in shallow ~10-15ft water when I notice my fellow classmate on the surface. I figured he just had buoyancy issues in the shallow water. We get out and found out he ran OOA and that's why he was on the surface. Luckily we were shallow and probably had already done a safety stop by the time he went up.

@midwayman: Was your fellow classmate your buddy on that particular dive? Just curious.

2nd was a trip to Punta Sur. We had discussed diving the Cathedral there, but several of us were uncomfortable with devil throat. We get in and have to go down super quick, and I'm having trouble clearing that fast. Eventually we get down and through the Cathedral, and our divemaster decides to take us through the devil's throat anyways. 4/6 of us come out the other side and we're hanging out at 120 while the divemaster goes looking for the other two. Eventually found they surfaced rather than go through. Shortly after that, one of the guys goes OOA and has to buddy breathe with the divemaster on the way to the surface. Get up, and he says he had a panic attack down there at 120, and one of the people who came up early had a bad nosebleed. Just a disaster of a dive.

One DM was taking 6 relatively inexperienced divers, presumably not trained specifically for diving deep, into an overhead environment. The depth made narcosis a very real possibility and gas management a critical issue on the dive. To top it all off, I bet the divers only used AL80 tanks. Based on info in the OP's post, it's pretty clear that the divers involved were abdicating gas management responsibility to the DM. What could possibly go wrong?

Last one was the next dive. It was nice and shallow, and my wife starts up early and I follow her up. She grabs my octo and starts buddy breathing at the safety stop. I find out up top she kept trying to tell the divemaster she was getting low, and eventually went up on her own. She wasn't completely out at the safety stop, but well into the red zone.

@midwayman: How did your wife's low on gas situation make you feel?
After all, she is carrying your emergency reserve gas.
What might have happened if you had encountered some sort of difficulty near the end of the dive? Do you think she would have been able to help you out...or would she have had to surface due to being low on gas?
There's a lot to think about from this incident.

 

[boulderjohn]

You did the Cathedral and the Devil's Throat in one dive?

These sites are in two different locations, with a third location in between. You have to keep on the move throughout your dive to do all three sites.

I did that once myself. It was a very special dive arranged for that purpose. Only advanced divers were allowed to do it, and only one DM in the operation (the operation's manager who did not normally lead dives) does it. It required the use of nitrox, since otherwise we would be well into deco by the time we were done. It required the use of steel HP 120 cubic foot tanks, and none of us could have completed the dive safely on an AL 80.

What operator were you using for this dive?

 

[midwayman]

Yah, I don't get it. My life is worth a lot more to me than a few extra minutes of bottom time. I guess this is why some of the big ops make people go up as soon as the first person drains their tanks.

 

[midwayman]

@midwayman: Was your fellow classmate your buddy on that particular dive? Just curious.

Well, it was the two of us and the DM. So yes? I know the DM checked in on gas during the dive but I never saw his readings. We were reasonably close, but facing the wrong way for this. Any you're right, I should have been more proactive about knowing where he was. If someone isn't specifically responsible, it normally ends up that nobody is responsible.

One DM was taking 6 relatively inexperienced divers, presumably not trained specifically for diving deep, into an overhead environment. The depth made narcosis a very real possibility and gas management a critical issue on the dive. To top it all off, I bet the divers only used AL80 tanks. Based on info in the OP's post, it's pretty clear that the divers involved were abdicating gas management responsibility to the DM. What could possibly go wrong?

After that dive, I would say that maybe half of us were qualified to be down there. I think the rest sort of got talked into it. I know I avoided Punta Sur last time I was in Coz since I didn't think I was ready. AL80s were the tanks.

@midwayman: How did your wife's low on gas situation make you feel?
After all, she is carrying your emergency reserve gas.
What might have happened if you had encountered some sort of difficulty near the end of the dive? Do you think she would have been able to help you out...or would she have had to surface due to being low on gas?
There's a lot to think about from this incident.

I never really thought of it in that light. I'm usually pretty on top of my gas consumption. Its something we will have to discuss though.

 

[midwayman]

You did the Cathedral and the Devil's Throat in one dive?

These sites are in two different locations, with a third location in between. You have to keep on the move throughout your dive to do all three sites.

I did that once myself. It was a very special dive arranged for that purpose. Only advanced divers were allowed to do it, and only one DM in the operation (the operation's manager who did not normally lead dives) does it. It required the use of nitrox, since otherwise we would be well into deco by the time we were done. It required the use of steel HP 120 cubic foot tanks, and none of us could have completed the dive safely on an AL 80.

What operator were you using for this dive?

That's what we were told. That we would be going to the cathedral. Shortly afterwards we were at Devil's Throat. I don't know if the DM missed the drop, or what. They weren't very far.

I'm not here to name names. They are a very respected op on this board though. If you really want to know, PM me. I'm not posting it publicly.

 

[AzAtty]

You did the Cathedral and the Devil's Throat in one dive?

These sites are in two different locations, with a third location in between. You have to keep on the move throughout your dive to do all three sites.

I did that once myself. It was a very special dive arranged for that purpose. Only advanced divers were allowed to do it, and only one DM in the operation (the operation's manager who did not normally lead dives) does it. It required the use of nitrox, since otherwise we would be well into deco by the time we were done. It required the use of steel HP 120 cubic foot tanks, and none of us could have completed the dive safely on an AL 80.

EXACTLY the way we did it. And going from Cathedral to DT? That's sort of...unusual in my experience. DT's exit is deeper than the Cathedral and upcurrent from it, iirc. If you did Cathedral and then DT from the shallowest entrances, you were sawtoothing on the dive and kicking against the current. No wonder you had air problems. When I've done it, we drop into DT at 80-90 feet, book it to the exit at 120-ish (deeper, actually, if we exit on the bottom of the "window," then haul over to Cathedral, enter from the deep side, and come out on top.

Coz can be deceptive because it seems so peaceful and warm. In reality, you can burn a lot of air even on shallow dives if you're flitting around chasing varmits, which will set you fighting the current without knowing it.

It also sounds like people weren't watching their gas. That's just inexperience being overwhelmed by the excitement and beauty of the site. Or just plain lack of attention. I got in the habit of doing a "gauge sweep" every couple minutes.

That's not to say that I haven't been guilty of draining my tanks in Coz. I've come up pretty close to dry a few times (never OOA and I was entirely aware that I was doing it). I know--do what I say, not what I've done.

 

[AzAtty]

I know I avoided Punta Sur last time I was in Coz since I didn't think I was ready. AL80s were the tanks.

IMHO, you simply cannot SAFELY do the DT-Cathedral run on an 80. According to my dive plan, a 120 is marginal if your consumption rate is high. With an 80, you don't have any reserve whatsoever unless you just plan a bounce dive. You were smart to avoid it the first run.