Colorblind before blackout?

[Theodoric]

I've honestly only pushed myself really hard a couple of times in regards to apnea, most times I just give in to the urge to breathe. The first time was at night, with very dim light, but towards the end of my hold, I thought the ceiling was turning a greenish/gray color. The second time was just a couple of days ago, and I swear I watched my vision slowly fade from color to black and white.

I've still never BO'd, so I guess I don't really know what that's like, but these instances were certainly nearing my limits. Has anyone else experienced anything like this?

People always say that BO's come without warning, but I just can't believe that's true. I remember Eric Fattah once saying he knew his body well enough to sense a BO coming. The "without warning" part must be due to the retro-active memory loss.

You'll have to excuse my inexperience and lack of knowledge, but if I go colorblind when nearing my limits, isn't that a pretty good sign of a BO? I guess I would have to BO for real to know for sure.

 

[cdavis]

We used to call it the "greys" usually comes with tunnel vision. Its related to samba, and yes, it means you are very close to BO. I have only experienced those symptoms when doing stupid stuff like hyperventilating like mad so I could go back down real quick and shoot another fish. Most of my buddies experienced one or two bouts of the same thing before it scared them (and me) enough to get more conservative and safety conscious. None of them have experienced those symptoms since then (40 years back) even though some are still diving and we have pushed pretty hard more than once. I often wondered if the symptoms were characteristic of divers just learning to push their limits or whether we just stopped pushing that hard.

Interesting aside, none of that group of divers have ever BOed either.

Retroactive memory is often a factor, but BO can come with absolutely no warning and no short term memory loss either. I've witnessed one just like that. The whole subject is an area where there is a lot of individual variation and where we don't fully understand what exactly is going on.

Connor

 

[MikkoP]

I've still never BO'd, so I guess I don't really know what that's like, but these instances were certainly nearing my limits. Has anyone else experienced anything like this?

Yes, I use the changes in my vision as the main factor when deciding when to come up at the end of a maximum DYN, DNF or static. The loss of color vision is called a "grey-out".

People always say that BO's come without warning, but I just can't believe that's true. I remember Eric Fattah once saying he knew his body well enough to sense a BO coming. The "without warning" part must be due to the retro-active memory loss.

At least for me the BO gives plenty of warnings, a very clear grey-out and sometimes also tingling in the limbs. I remember the signs very well, if I come up early enough, but if I push it too much, to a bad samba or BO, I can't really remember anything from the end of the dive. I'm sure the warnings were there, I just failed to listen to them when thinking too much about meters or seconds.

I don't know, maybe it is possible for some people to have a BO without any warning, but I think in most cases it's more about just ignoring the signs, or not knowing what they mean, during the dive and not remembering them afterwards when the short term memory is lost.

 

[Bill]

The answer to your questions is yes. Just don't rely on it because there are too many variables. For most of us, the first blackout results in pleasant feelings followed by disorientation (What am I doing here? Why am I on my back? Who are these people with long faces looking at me?) and denial (I don't remember blacking out so it couldn't have happened.)
We had one member who was doing super long statics until he videoed himself. After 6 or 7 minutes he stopped squirming, exhaled, froze for a moment, took a breath and stopped the watch at world record time. Fortunately he was on his back in bed.

 

[salibandy]

I have never blacked out. However, I've come pretty darn close. What happens is that my vision will fade away to nothing, followed by severe disorientation. After a while, things will return to normal in reverse.

I once almost blacked out while cycling in Australia. I cannot take the cold, and it was my first time exerting while breathing cold air. I remember my vision fading to green, and when that happened I immediately stopped, got off my bike and knelt down.