Dizziness During Ascent

[talonraid]

On two separate occasions now I have experienced some short lived (less than 2 or 3 seconds of dizziness during an ascent.

Both times it was near the surface. The first time was actually in a 10 foot deep pool during OW class. The ascent was slow and deliberate. I was maybe a foot from the surface. I suddenly experienced sort of a "rush" in my head followed by what I estimate to be 2 seconds of dizziness prior to reaching the surface. Then the sensation went away and I felt fine the rest of the day.

The second time was after a dive in Cozumel down to about 65-70 feet with a slow ascent (less than 30 ft. per minute) and a nice leisurely safety stop of about 5 minutes in 15-20 feet of water. Then, like the first experience maybe 3-4 feet from the surface this time I had a "head rush" followed by a short spell of dizziness, then whalah! Gone. I felt fine.

During both incidents I was ascending slowly...I always ascend painfully slow. Both times I felt unnerved during the sensation, but concentrated on maintaining my breathing, good ascent rate and visual contact with my buddy. I could see however how someone could lose orientation or panic with the sensation.

Anyone ever experience this or hear of this?

 

[TSandM]

This is likely to be alternobaric vertigo

 

[Knight]

Maybe you should talk to someone like a DM or a dive doc about this and see what they have to say, being in the commercial field I heard a story of a diver who complain about the same thing and during a work dive at the descend he some how another blacked out and before the emergency diver could even gear up it was way too late. You need to get things like that sought out by experts of why this is occur and if it will at all affect you diving at some point, since it doesn't seem you have found out a true answer.

Always descending,
c.h.

 

[Rick Murchison]

This is likely to be alternobaric vertigo

Yep, yep... almost certainly.
Rick

 

[TheVinstigator]

this was happening to me also, started in the pool sessions during my OW class. Are you equalizing on ascent?? You Sure?? I thought I was also but in reality I wasn`t, now I equalize often and haven`t had it happen to me in 170 dives. Do you also hear a crackling in one of your ears when it happens?? You should always keep your buddy informed that this might happen so they can keep an eye open for it near the surface.

 

[stardiver]

You might want to see a physician to rule out any medical issues...
*medical disclaimer over*

That said, and knowing what you know now about vertigo, how do you keep from having this feeling?

On ascents, descents, and even when just swimming along, this feeling can be worsened when you have no visual reference due to limited viz. If you are ascending, slow DOWN and find something fized in the water column - the ascent line, a wall, a buddy, sometimes even a fish will do. Shoot a lift bag if you have one; the line will give you something to look at. If the visibility is good enough, look at the bottom. At least you'll have perspective as you move towards or away from it.

If you have nothing stationary on which to fix your gaze, look at your depth gauge or computer and breathe while becoming neutrally buoyant until you are feeling more steady - stop, breathe, think. Just knowing that you are really not moving up or down can be very settling.

This happens to me most often in low viz situations. I know this, and plan ascents and descents around it as best I can, knowing that the feeling is just that, a feeling, and can be dealt with.

Good luck

*

 

[alo100]

Both times it was near the surface. The first time was actually in a 10 foot deep pool during OW class. The ascent was slow and deliberate. I was maybe a foot from the surface. I suddenly experienced sort of a "rush" in my head followed by what I estimate to be 2 seconds of dizziness prior to reaching the surface. Then the sensation went away and I felt fine the rest of the day.

I bet probably more than one person has experienced this before...

Quoting something from Pipedope about partial pressure in shallow water, his comment was orginial related to rebreather in pool (or in general shallow water) accident:

"In many ways, rebreathers are MORE DANGEROUS in shallow water.
The faster changes in volumes and PPs (partial pressures of gasses) cause more problems not less."

 

[talonraid]

Thanks for all your comments. I read a little about alternobaric vertigo and it sounds likely that this is a possible culprit.

I also talked to a couple of instructors and even had the doc (who happens to be my dive buddy) check my ears. No problems on a physical examination.

I typically don't worry about clearing on the ascent, because my ears tend to clear on their own. But, I think I'll start actively opening the eustachian tubes on ascent and see if it ever reoccurs. Once again, thanks for everyone's input.

 

[hilti]

I had a dive earlier this year where I experienced something like what you describe, but the visibility created a new experience for me. I always start my shore dives from the shallows, and follow the contour of the bottom to a max depth I'm comfortable with, on this particular dive I had dropped to 60 feet and became confused by the difference in the bottom contours than I expected (I usually take a comass bearing on my "end of dive" point), but this time I expected the drop off would be typical and follow the shoreline ~and it wasn't. I decided to surface and get the bearing I normally take and halfway or so through it without a visual on the surface or the bottom I experienced dizziness. I corrected the problem by swimming horizontally at that depth (some 30 feet) until I could see the bottom and then continued the ascent. This leads me to believe that without a visual reference to establish depth perception in a weightless environment it's fairly easy to experience vertigo/dizziness. This is the first and only time I've had this happen, my job most of the time requires that I work far from the ground, typically 80 to 90 feet, although I have worked jobs that took me to heights in excess of 1000 feet. I have not ever experienced vertigo or dizziness and attribute the incident to a loss of visibility to a visual reference. It's just my impression after the incident, I haven't experienced it since and don't expect to.