Disorientation and uncontrolled ascent on night dive

[geogator]

One thing that I have learned is that if I ever begin ascending too fast in a dive (low viz or not), my ears will pop before I've ascended very far. (usually by 10-15 feet) I kind of consider that to be my body's way of giving me an extra warning to slow down and pay attention, especially if I happen to be distracted by something else going on or task loaded at that particular moment. (ex: adjusting gear, etc.) When I've felt them pop in such a situation in the past and I've looked at my computer, 9 out of 10 times it's close to blinking "too fast". I guess that's a good sign that I can be that in tune with what my body is experiencing and trying to tell me?

 

[phoenix31tt]

one moment I was perfectly fine, neutrally buoyant and then suddenly, I could see people oriented strangely and apparently descending.

I noticed you signaled before trying to exhale... when in a situation like that try taking corrective action first before signaling as the precious seconds could've been the difference between arresting the ascent and racing to the surface...

anyways i'm not sure if anyone mentioned this before but a few things:

1. you may need to pay more attention to your neutral buoyancy... with what you were diving, at the start of the ascent, a full exhale should've made you negative (or at very least arrested your ascent). At that point in the dive your wing is not supposed to have so much air as to have you positive on an empty lung, actually at no point in time in a dive this should be the case (at least in rec diving, idk about tech)

2. in an uncontrolled ascent (since most of your buoyancy will be on your back, tank and bcd) you will most likely face down or feet down, this may be helpful in determining your position in the water... either position would allow you to vent from your corrugated hose.

3. You were seeing your buddies/dm... after you noticed you were ascending and tried to signal, try swimming toward them... using them as your reference would've helped with the disorientation in general.

 

[Iralub]

Thanks very much phoenix. I confess that trying to swim towards buddy/people didn't occur to me and may well have helped.

In terms of breathing, I definitely started exhaling immediately when I realised I was ascending, at the same time as trying to signal and dump air. I just wrote up the actions and their consequences in a particular order, which unfortunately appears to have misled several people. My bad.

Because my lung capacity is small (I'm a very small, thin woman), generally breathing out will not stop my ascent if I'm already positive enough to be ascending. I will have had air in my bc as I was at about 15m depth, with 5mm wetsuit and I suspect it and suit expansion would generate greater volume expanding than my lungs could counter.
I guess that raises the question that boulderjohn raised re whether I was weighed properly too.
And I agree that I probably need to pay more attention to buoyancy control - I was finding it harder diving in a thicker suit than is normal for me (only used 3mm before) and the greater buoyancy changes. Definitely something to work on.

 

[phoenix31tt]

I was finding it harder diving in a thicker suit than is normal for me (only used 3mm before) and the greater buoyancy changes. Definitely something to work on.

yes, definitely a 5mm has more buoyancy swing than a 3mm suit so that's something to get used to... once your weight is dialed in and you get accustomed to the buoyancy swings of the 5mm you'll get it down...

 

[ev780]

Don't feel bad it happens to everyone??????? Lol it is potentially fatal accident. Not that unusual but iit is bad. The biggest issue I have with the scenario is that the op thinks that the initial strategy is to wave lights and signal. That is a total Fail !! You need to exhale hard and fast and take care of yourself. There is no way a buddy is going to know wth a waving light means in the dark and then what are they to do., shoot up and rescue you??? Completely wrong mindset

Our pilot friend in this thread will appreciate this.

Aviate--Fly the BC. Try to get control.
Navigate--Try and get pointed in the right direction
Communicate---Then get some signaling done.

Not a perfect comparison but helps. Sounds like you tried to get control but without success at the same time you were signaling. Maybe a little more focus on solving the problem rather than communicating it to those around you. {shrug} Wasn't there and it all worked out fine. Just an unplanned surface as it turns out rather than a dangerous uncontrolled ascent.

With screwy sinuses I can lose my orientation sometimes too. Hard thing to get back especially if you lose your visual reference too. (two methods of finding your space and time are now gone) Maybe some under the hood work (continuing with the flight comparison) will get you prepared again. Somehow take away a sense and work with that. Obviously needs to be done in a controlled manner but desensitization can help. It helped me learn the pre-symptoms and control my positioning better.

All in all just a learning experience.

 

[Iralub]

Some random thoughts...

I would assume it took you less than a minute, but you should be able to tell by looking in the dive log of your computer. If it had taken you a minute from that depth, that would have been a little slower than the old recommended 60 FPM ascent rate. Most uncontrolled ascents are much faster than that. Still, your description sounds as if it did take a while, long enough at least for you to realize something was not right, look for your bubbles, signal for help, try to dump air, etc.
.

I just got a cable to enable me to download my dc data. It shows that I was at 16m when the incident began. I initially ascended within the padi rate (7m/min, increasing to around 13m/min) until I got to about 10m depth, when the ascent rate was over 23m/min.

So it looks like I did blow the padi limit (not surprising really).

Lucky that nothing happened I guess

 

[boulderjohn]

I just got a cable to enable me to download my dc data. It shows that I was at 16m when the incident began. I initially ascended within the padi rate (7m/min, increasing to around 13m/min) until I got to about 10m depth, when the ascent rate was over 23m/min.

So it looks like I did blow the padi limit (not surprising really).

Lucky that nothing happened I guess

Still, it's not as bad as you seem to think. You could have done a lot worse.

 

[Macan]

I just got a cable to enable me to download my dc data. It shows that I was at 16m when the incident began. I initially ascended within the padi rate (7m/min, increasing to around 13m/min) until I got to about 10m depth, when the ascent rate was over 23m/min.

So it looks like I did blow the padi limit (not surprising really).

Lucky that nothing happened I guess

TS gave you very good advice. It was also a situation and sensation that you've never encountered before. The ascent rate was fast at 75ft/min but as Boulder said, it could have been worse. You kept your cool and properly assessed your situation and took proper actions like exhaling and signaling. Your request for O2 on the boat should not have been pushed aside by the crew. As it turned out, you were right about your fast ascent rate and breathing O2 post dive would have been the appropriate cautionary step to take.

May I suggest that the next time you determine that you need O2, please insist on it, irregardless of what the crew says.

 

[Iralub]

TS gave you very good advice. It was also a situation and sensation that you've never encountered before. The ascent rate was fast at 75ft/min but as Boulder said, it could have been worse. You kept your cool and properly assessed your situation and took proper actions like exhaling and signaling. Your request for O2 on the boat should not have been pushed aside by the crew. As it turned out, you were right about your fast ascent rate and breathing O2 post dive would have been the appropriate cautionary step to take.

May I suggest that the next time you determine that you need O2, please insist on it, irregardless of what the crew says.

TS always gives excellent advice that I absolutely intend to follow

To be fair to the crew, I didn't ask for O2 but rather queried whether I should breathe some. As I wasn't showing any symptoms they advised me to monitor myself and let them know immediately if I was experiencing any.

I think you are right and it would have been wisest for me to ask for some as a precaution, but I asked for their opinion and they gave it to me, so can't really blame them. I think if I expressed it as a request it would have been followed.

 

[Hintermann]

Disorientation with regard to body position is quite common (perhaps more so than we think) during dives, even day dives with excellent visibility. There have been times when I was 100% that I was as close to being perfectly horizontal as I possibly could but as I got closer to the surface, the sea surface above appeared to be "sloped". Sometimes this can be due to orientating ourselves parallel to the reef floor (if that is within dive depths) that we think is flat but which isn't. Paradoxically, I have noted this disorientation most in best visibility and seldom on night dives and so there relally is something in the gen about disorientation in very clear waters.

A very good example of level disorientation during day or night dives is the "Russian Destroyer" wreck in Cayman Brac. That has a list which needs to be taken into account during exploration; it is very easy to keep parallel to the wreck and end-up lop-sided for rest of the dive.