Should I be dead? (Last night's dive)

[ScubaSky]

I know every point has probably been hit by now, all I have to add is that "Hind sight is 20/20" learn from the mistakes you made.

The Training you already have should have helped you learn from other peoples Mistakes. IMO air sharing should not be a regular practice on your dives.

Lastly if you can't afford to dive SAFELY don't dive.

 

[MikeFerrara]

I thought I'd bring up another thing since the subject has gone the way it has. Around here we see a lot of rapid ascents. The water's cold and regs free flow often and usually result in a rapid ascent. Air sharing situations go the same. It's not at all uncommon for divers to loose control of position when in such a situation. There are lots of reasons for this but it starts with entry level training. Most OW classes teach divers to share air while kneeling on the bottom. We need to learn it midwater and we need to practice it midwater. I have had divemasters and instructors come to me for Advanced Nitrox classes and they can't do these things and maintain depth. I see the exact same issues when divers try to deploy a bag or tie a knot in a line. They go vertical, change breathing and notice when their head breaks the surface.

There are two things that will start a buoyancy change. The first is a change of breathing pattern which is a natural reaction when things are going wrong that must be controlled. The second is a change of position. It's natural for people who go through life standing up to want to go vertical when they get busy. Teaching these skills while kneeling on the bottom does nothing but reinforce this vertical posture. When sharing air or doing anything else, though, it's important to keep position constant (horizontal) and get breathing under control.

Combine all that with a loss of reference and the reult, 9 out of 10 times, is a uncontrolled ascent or descent. Divers are simplu NOT trained to handle these things in a real diving situation.

People keep argueing the point and I keep seeing, hearing and reading the same thing over and over.

 

[crispos]

You did OK, kid. You are still around, and you are taking this very seriously, and baring your soul. Lucky you are young, that's why you didn't have any DCS so far (or are you at the chamber now?).
We all made mistakes at your age, and you will be a better diver.

Wrong, communication wasn't the problem. It was dive planning. The problem was you went down to 120 feet without enough air and without redundent air. When the **** hits the fan, it is pretty hard to perfectly coordinate buddy communication, looking at your (probably difficult to see) depth guage. Also, as was pointed out, you skipped the buddy check part with the octopus. Bad.

Some people think a threesome isn't a great idea. Too many arms in the way screwing with the same problem.

Plenty of people have started a rapid ascent without realizing it.
Especially at night, it's hard to tell. Nice work doing the deco stop afterwards. I believe you probably saved yourself from DCS there.

Yeah, your dive looks like a cliff in reverse. Thanks for providing a profile. All the best.

 

[Karl_in_Calif]

asemili once bubbled...
Does anyone have any oberservations or comments? How dangerous was this situation? Was it seriously as grim as it seemed or where we fairly safe?

A deep night dive is a serious dive, and you want to be buddy independent.

You can get a Uwatec bottom timer for about $150 to $200.

Then just remember MOD + B/T = 120 max.

 

[paulwlee]

Looks like you were OK until about 30ft or so. Ascent rate looks like 20ft/min until then, and maybe a little over 60ft/min to the surface. So the profile for the first part of the dive looks better than you described it, and within what a lot of people get away with all the time, although potentially dangerous. I guess you were drifting up from 60ft without realizing and then accelerated at the end.

Now the second part looks really scary. I'm glad that you all came out of it alive.

What I wanted to say people have already said many times, but I'll say them anyway.

1. Check your weight: I'll believe you that you aren't grossly overweighted, but still, you will probably be able to drop a few lbs.
2. Wrist computer or depth gauge on right wrist works waaaaay better than a console. See if you can get a wrist boot for the depth gauge in your console, if you don't want to buy another one.
3. Make sure octo hoses are long enough to be used effectively. (I actually switched to a 5ft hose that I like immensely, but some will say that's overkill.)

 

[Charlie99]

You need to stop and think before acting. This particularly aplies to the uncontrolled descent with little air immediately after you surfaced. A discussion, decision and plan would have taken less than a minute.

Remember the old STOP, breathe, think, act adage.

While some have postulated nitrogen narcosis as an aggravating factor, it looks to me more like good ole adrenaline, excitement, and fear ---- all of which interfere with good judgement.

Charlie

 

[Aquatic Eagle]

All I have to say to this whole thing is that I definitely recommend practice for all three of you. Get yourself very comfortable with all of the skills before you attempt a deep, night dive again. Also, make sure that communications between you and your buddies is very clear. You should be able to communicate any problems to your buddy with no problems whatsoever. Glad to see you're ok now and be safe.

 

[wetman]

One thing that might help - when I do free accents and its dark or black, its helpful to take your light and point it horrizontally accross the water out in front of your face. (and not pointing at anyone of course.) This gives you a fantastic visual reference in the water - all the floating things are very well lit up. As mentioned in a previous post - those are your reference - if they go up, you're going down. If they go down, you're going up. Based on how far away you're focussing, you can also get a feel for how many feet and how fast in either direction. You shouldn't need a line for an accent at all - it is a crutch that i think we all start out with and should quickly learn to leave behind. The last thing you need to do right now is get a lift bag and reel - you need a bit more experience before you add that to the repertoire i'd think. And you'd need to use it for the right reasons - providing yourself a visual reference isn't one of them. Focus on the basics first then add one thing at a time. Consider this your wake up call - many of us have one and it usually changes the nature of your diving from then on for the best. You'll now appreciate just how things can screw up incredibly quickly and you wont be so quick to put yourself in that position again.

steve

 

[VTernovski]

Mike, you hit the spot right there! This is probably the most valuable post I have encoutered in a long time.

-Vadim

MikeFerrara once bubbled...
I thought I'd bring up another thing since the subject has gone the way it has. Around here we see a lot of rapid ascents. The water's cold and regs free flow often and usually result in a rapid ascent. Air sharing situations go the same. It's not at all uncommon for divers to loose control of position when in such a situation. There are lots of reasons for this but it starts with entry level training. Most OW classes teach divers to share air while kneeling on the bottom. We need to learn it midwater and we need to practice it midwater. I have had divemasters and instructors come to me for Advanced Nitrox classes and they can't do these things and maintain depth. I see the exact same issues when divers try to deploy a bag or tie a knot in a line. They go vertical, change breathing and notice when their head breaks the surface.

There are two things that will start a buoyancy change. The first is a change of breathing pattern which is a natural reaction when things are going wrong that must be controlled. The second is a change of position. It's natural for people who go through life standing up to want to go vertical when they get busy. Teaching these skills while kneeling on the bottom does nothing but reinforce this vertical posture. When sharing air or doing anything else, though, it's important to keep position constant (horizontal) and get breathing under control.

Combine all that with a loss of reference and the reult, 9 out of 10 times, is a uncontrolled ascent or descent. Divers are simplu NOT trained to handle these things in a real diving situation.

People keep argueing the point and I keep seeing, hearing and reading the same thing over and over.

 

[Cave Diver]

Since I'm arrving rather late to this thread and everyone has pretty well covered the weight/training/narc'd/experience/dive with the proper equipment stuff, I'll address something that seems to have been overlooked.

asemili once bubbled...
Btw, do the math on the dive and you'll find that we ended within NDL. Not within much, but like right on the line. Fortunate, yes, but still within NDL.

There is no "line." No person, computer or chart can accurately predict when or where a DCS hit will occur. The NDL's are a "best guess" model. There are many predisposing factors to why someone gets bent and why someone else on the exact same dive doesn't.

Don't lull yourself into a false sense of security because you were "right on the line" and got away with it. Rapid ascent, heavy exertion swimming back to the boat, increased heart rate from panic/adrenaline, could all easily have contributed to "crossing the line."