This is actually an old incident, but a member found it in the old dive reports, and it would have been put here back then, if this forum had been around at the time.
Reported By: Angie Reim & John McMacken
Report Date: 7/24/2002
Location: Lightening zap on the Hill 400 at Ginnie
A Dive Report In Two Voices:
(Angie) After lunch on the day of the social, John and I decided to try our first staged dive. The general plan was to head up the mainline, drop the stages at thirds and swim up the Hill 400 Line until we hit thirds on our back gas. Both of us had practiced carrying Al80's earlier, but neither of us had breathed from them before. While gearing up we saw a storm coming from the distance but decided that we would be better off below than in a pavilion under a tree (uh huh…). We waited for a pair of divers leaving the Eye and also allowed a team of four to pass us before attempting to carry the stages through the Corn Flakes. We dropped our stages at the junction room. I noticed that the current was so strong that the tanks were traveling along the mainline with it. A strategically placed line arrow took care of the problem. We continued up the mainline to the Hill 400 jump. I set the jump spool and we headed up Hill 400. When we made it to the slope that takes you from ~93 ft to ~75 ft I checked my air and found that I was still about 500 psi from turn. That meant that John was about 600 psi from turn. As I reached the top of slope, I noticed John signaling to me to turn the dive. I thought it strange but I was not concerned. At that exact moment I had a headache that rapidly increased in intensity to excruciating. As I faced forward just before turning around, I saw lights dance before my eyes and it felt like someone had thrown a shovel full of sand into my face. I felt dizzy and a warm flush over my body. My first thought was of O2 toxicity. I lost trim and John was at my side. I signaled that something was wrong and pointed to my head.
(John) I turned the dive because I heard the Voice, and the Voice said, "You don't want to be here right now, you want to be back at the pavilion having a few beers and meeting people". I always respect the Voice, so I signaled Angie to turn around. That's when I felt a short convulsion run through my body, like all my muscles locked up and released. What the hell? I check Angie and see that she is signaling a problem too.
(Angie) We are conservative in our dive plans and never exceed 1.4 ppO. I prefer to stay at 1.2 or 1.3, but given the symptoms, it was the first thing to enter my mind. While attempting to recover, I noticed that we had drifted back down the slope to 94 ft. I was feeling better, so it could not have been O2 toxicity. John seemed unaffected so I thought maybe I had a stroke. I OK'd the line and we started out. We traveled a short distance when I had a convulsion. All my muscles tightened and my jaw clamped down on my regulator. I found myself holding the line, conscious, breathing and floating like a stunned fish. I could not move!
(John) I notice that Angie is exiting on the line, so I know she is having problems. Then a second convulsion hits, much stronger than the first. I look back and see Angie in poor trim, drifting towards the cave floor. Her reg. is in her mouth and she is breathing. What's going on? I start to think of oxtox convulsions. We both got fills from the same place at the same time, banked EAN32. I watched them analyze the gas. It was OK. Did we somehow get a hot mix? Or was the gas contaminated by something? What would cause both of us to get distressed at the same time? The only descriptions I had heard of oxygen toxicity spoke of full grand mal seizures, not intermittent convulsions. It is very lonely to be 900' back in a cave and think that both you and your buddy may have a compromised breathing supply. I figure our only option is to exit as quickly as possible, but at the same time we don't want to build up a lot of CO2. Keep calm and use pull and glide. I give Angie a vigorous thumbs up, but she responds weakly and does not move. I grab her by the manifold and head toward the main line.
(Angie) I recall John returning to my side and calling the dive with extreme urgency. It was all I could do to look at him, widen my eyes and give a feeble thumbs up. I was still unable to move. I was immensely relieved when John grabbed my manifold and started dragging me out. He carried me about 300-400 ft. By the time we hit the mainline, I was kicking and pulling and gliding on my own. I also had figured out that lightning had shocked me. I'm a native Floridian and the symptoms matched the stories that I have heard over the years. I was no longer worried about our air but I was worried about another shock. We left my jump reel in place. I OK'd the line all the way out of the system. We stopped to get our stages. I did not breath from mine because I had too short a hose and figured I would lose the regulator if shocked again.
(John) By the time we were on the main line Angie was moving on her own and feeling well enough to return an "OK" to my question. I had not felt any further symptoms and figured that if our gas was bad we would have been dead by now. We were after all about 20' deeper than on Hill 400. But what had happened? I was still clueless. We did pause to pick up our stages in the Junction Room. We were a long way from the exit and I thought more gas was better than less.
(Angie) We deco'd in the Eye and I wrote a note telling John that I thought I had been hit by lightning. Until that moment, I thought that he had been unaffected but he too had felt the strikes. There was a storm passing over and we could see the lightning from the bottom of the Eye. It was scary.
(John) I didn't figure it out until Angie passed me a note during deco. We had been zapped. It matched the symptoms and the rather spectacular light show we were getting in the Eye. I think our training paid off; we didn't panic, we did our best to analyze the situation and got out of the cave safely. We were also lucky. If this had happened in a tight, silty passage, things would have been much more difficult.
(Angie) Don't believe conventional wisdom. Never dive when there is lightning in the sky. Ninety plus feet of rock and water won't protect you. We were incredibly lucky. We could have lost consciousness, lost our regulators and both been immobilized. We could have died. I think we handled the situation as best as anyone could have. Dive safely. Angie Reim, John McMacken