(posted Jan 4 2010) So, Saturday, my husband and I did a planned staged decompression dive at Whytecliff Park in Vancouver. The plan was a max depth of 130 and no more than 15 minutes of deco (which we knew we wouldn't reach). We were diving 25/25, with O2 for deco gas. We used scooters to get out to the wall, and the deep portion of the dive was uneventful. We averaged significantly shallower than our plan (which is not unusual) and actually had only about five minutes of mandatory decompression when we left the wall at its top, at about 50 feet.
We started swimming toward shore, and I was following the reciprocal heading we had used coming out. Peter wanted to get us shallower, following the deco plan, so I signaled that I wanted to get on the scooters, because my thought was that, rather than swim and do deco in midwater, we could follow the contour up if we could move faster. He didn't understand why I wanted to get back on the scooters, and he signaled to move up to 20 feet, which was our gas switch depth. I okayed that, but didn't move up as fast as he did, so he disappeared from my view. I am now in midwater with no visual reference and have lost visual contact with my buddy.
I have had serious problems with vertigo in midwater since I started diving, and only about a year ago did someone give me the key -- rapid head movement with no visual reference will start me tumbling. Since I got that piece of advice, I haven't had an episode. But on this dive, I was really worried about losing Peter, because we were both on scooters, in fairly poor visibility. If I continued to motor without being able to see him, it was highly likely we'd get separated, as we'd been disagreeing on the heading all along. If I didn't get on the trigger, we were SURE to be separated, because I could hear his scooter motor running, and it would only take seconds to be unable to see one another.
So I began looking for him actively, which involved rolling up on my side and turning my head repeatedly . . . and sure enough, after a couple of iterations, the world broke off its moorings and began tumbling and spinning, and I lost all sense of where up was.
In every prior event like this, I have ended upon the surface. I knew I couldn't afford to do that this day. I couldn't use the scooter, because I didn't know which way was down -- but I knew if I exhaled and vented, I'd sink. The bottom was no deeper than 50 feet, and I was a lot safer hitting it than hitting the surface. I was clawing at the water with my hands, completely disoriented and trying desperately to use the tools I've gained from cave training to get myself sorted out -- where were my bubbles going, and how did my drysuit feel? I finally got to where I knew I was going down, and began trying to arrest my descent and overshot, and yo-yoed badly a couple of times before I got things under control. I could see Peter flashing my hands at one point, but there was NO way I was going to try to look up at him. (I should have given him a "hold" signal, but I didn't have enough processing power at that point to think of it.) Finally, at about 30 feet, I got stopped, got stable, got my breathing and my heart rate under control, and could begin to try to dive again.
Lessons learned:
1) I KNOW I can't search for a buddy in midwater. I shouldn't have tried. If you can't stay where I can see you, you need to stay where you can see me, and be aware that it's YOUR problem at that point.
2) I got it stopped. I could never do that before. I have gained tools from other training that were directly applicable here. No training is ever wasted.
3) It is useful to be able to decide quickly what the biggest danger is. In this case, it was being too shallow. Being too deep I could deal with, and was going to be limited in any case by the hard bottom. Once I decided shallow was bad, I knew what I could do to avoid it, even if I didn't know where I was.
4)
If you have a weakness, don't ever think it's been overcome. It can sneak back and bite you at the most unexpected times. Constantly work on the things where you have problems (or, as my wonderful cave instructor said, "Just because you aren't good at something isn't a reason not to do it. It's a reason to do it more often."
http://www.scubaboard.com/forums/ne...-learned/318124-vertigo-deco.html#post4948568