Shallow Water Black Out-Sort Of

[HawgLeg]

I am new to the board and pretty new to the underwater world with only 6 OW dives in my book.

So onto the event:

I know shallow water black is usually experienced by free-divers but I am wondering if it can happen to divers as well, what I experienced seemed somewhat similar to what I have heard and read about SWBO.

Last fall while diving in a quarry I had a VERY scary experience. I was down about 20-25 on a platform and the viz was terrible (maybe 5-7 feet). I started to ascend with my buddy and around 10ft everthing starting spinning and I thought I was going to pass out. It hit me hard and fast with no warning. My breathing and heart rate went through the roof and I grabbed my buddy for stability and got to the surface. The feeling was gone within' 20-30 seconds of its onset. It really SCARED the hell out of me. The feeling was almost like a headrush when you stand up too fast but it was much, much worse.

The guys/girls I was diving with are instructors and they said my hood might have been too tight and It was cutting off the blood flow. Not sure if that is the case or not. I removed the hood and floated around for awhile until I had the courage to go back down. I tried to duplicated everything I did on my first decent to see if the symptoms came back and it didn't. Thank God. However, I am still very curious to figure out what caused this problem because I do not want to go through that again.

Anyway, if anyone has any suggestions please respond.

Thanks

 

[DavidPT40]

Sounds like vertigo with associated panic to me. Pilots can get it when the color of the sky too closely matches the color of the sea. I havent really heard much about scuba divers getting it though.

 

[Drew Sailbum]

I'd would hazard to guess you experiences alternobaric vertigo. This results when the equilibrium is disrupted when the ears experience substantially different pressures.

A too-tight hood could contribute to this. It could simply be that one ear was slower to release air from the middle ear due to mild congestion.

 

[cinder4320]

I agree with vertigo. The "weirdness" brings on a sense of panic if you do not know how to deal with it. I had a very similar experience when I first started diving (dive 2 after checkouts) and it was definitely vertigo. Since you mentioned it happened on ascent I bet you had some sort of inner ear imbalance. My vertigo also corrected quickly as my ears equalized.

Miranda

 

[D1v1n]

Here is a link that breaks down vertigo, I have had this happen before and it is unsettling, sometimes you just have to stop and steady yourself and it will pass. When I have had it happen the water has been cold, and I had difficulties with middle ear pressure equalization. Add cold water to the mix and it can feel like a freight train is running through your hood. Hope this helps.
http://www.scuba-doc.com/vert.htm

 

[spectrum]

Sometimes called the twirly bends. It usually happens on an open water ascent with no visual reference. The diver may be unknowingly revolving and ascending at a faster than prudent rate. The revolving,, lack of visual reference and inner ear pressure results in a wicked vertigo episode, It happened to my wife, oddly enough in a quarry.

When you ascend ride your depth gauge as a visual focal point and to control your rate.

Pete

 

[Chad Carney]

The twirlies is largely caused by cooling in the ear when expanding air evacuates through narrow Eustachian tubes. Just like an opened tank valve.

Chad

 

[dumpsterDiver]

I never heard that one.. about adiabatic cooling in the middle ear.... Maybe some decent thermodynamicist? can calc what temperature differential is possible during typical ascent rates?

I experience reverse ear squeeze somewhat often when scuba diving and it can cause terrible dizziness on ascent. It is very scary and can be so bad that you can not hardly see. The vertigo has been so severe that it has caused me to vomit, sometimes 60 seconds after the vertigo has completely cleared up..

As mentioned, this is caused by one ear not automatically venting on ascent. My solution to the problem is to immediately shoot back down to a depth where the pressure is equal and try to ascend slowly and rub my tongue on the roof of my mouth . Other times I have to remove the mask and blow my nose. This is much more likely to occur when diving shallow and making frequent depth changes which results in a relatively large pressure changes. I used to have a lot of trouble when diving on reefs in the 10-20 ft depth range.

 

[HawgLeg]

Vertigo or adiabatic cooling. Both of them sound like the culprit. It could be a combination of both.

I can tell you this, I will not be wearing a hood again and until I am 100% comfortable with the situation I will be riding my buddy's back on every ascent.

Thank you guys for the info!

 

[wulvrine74]

Something like that happened to me once at 110' in a cave. I actually hyperventilated and stopped breathing. I think maybe it was a mix between the cold water of the quarry and the low viz freaked you out. I'm sure thats what it had to be with mine. If you want more details on my story, read it here: http://www.scubaburg.com/florida-springs.html
Some of what you said sounds similar.