Spatial Disorientation?

[LakerPride]

Just looking for a little insight on what caused my experience last week. I was on an air dive with simple profile, max depth had been 89 FFW for 14 minutes on a wreck, I then ascended to 67 FFW for 22 minutes, then began to surface. My ascent rate was variable because of currents but was between 5-15. Around 35 ffw I lost sight of the wreck and soon after felt disoriented. I lost track of which way was up, I suspended my ascent, and descended to 45 ft where the wreck came into sight and I felt fine. I again slowly started to surface and again as soon as I lost track of the wreck felt disoriented, this time also it felt as if I had the urge to raise my head, as if I was assuming a "skydiving" posture. I stopped my ascent but did not descend, and within a few seconds felt fine. I never felt any pain, or discomfort, I continued my ascent without trouble but added a 15 minute stop at 10 ffw before leaving the water. I have not dove again since and it has been 8 days.

I have been diving a lot lately but had not dove in 72 hours prior to this dive. The dive prior had been an air dive to 127 ffw, without incident. I was not on any medication. I don't feel it is DCS related but not sure what to label it. Just wondering what may be causes of such disorientation.

Thanks

 

[TSandM]

It's almost certainly not DCS.

It's probably one of two things: Either you experienced alternobaric vertigo, where one ear releases the expanding air faster than the other one, and the difference in pressure causes balance problems and a feeling of tumbling, or you are like me, and exquisitely dependent on a visual reference for your orientation. I have battled, through the eight years I have been diving, the fact that midwater, with no bottom and no surface, often leaves me completely unsure of where up and down are, and unable to interpret my orientation or my motion in the water.

Years ago, I did NWGratefulDiver's fiendish midwater navigation dive as a volunteer buddy with one of his students. This dive involves going down to 20 to 25 feet in pretty crummy viz, so you can't see the top or the bottom. You have a navigation course to swim -- one buddy is responsible for monitoring the compass, and the other for keeping the team on depth and monitoring the time. Halfway through the first leg, I looked at my buddy and he was perfectly vertical in the water. I found that odd, because he was way too experienced a diver to be vertical. About that time, I realized my exhaled bubbles were running up my body -- my buddy wasn't vertical, I WAS, and head down to boot.

There are a number of ways to cope with midwater disorientation, and if you think that's what was going on, I can write some more about it. Not too many people share this problem, so it takes quite a bit of detective work to get good advice on how to handle it.

 

[LakerPride]

Do you have trouble with it when on a down line? I usually ascend and descend my anchor line on the wrecks, especially deeper ones, but this wreck is fairly shallow and was near the shipping channel so my wife had to move the boat while I was down, and I made a free ascent. Perhaps it is what you described, I would definitely be interested in hearing more.