IRAP Administrator
08-03-2007, 10:52 PM
My buddy and I were doing a gear checkout dive prior to an upcoming dive trip in Missouri. The purpose was to "work the kinks out" of a full-face mask he intends to use on the trip. He feels the full face mask to be absolutely necessary to accomodate some of his needs. We discussed ooa procedures prior to the dive, but neither of us had much experience with ffm's. He had 2 prior dives on the mask (hence the checkout dives) and I had never used one at all.
He felt comfortable enough to take it into deep open water in order to simulate the cold temperatures we would encounter underground on our upcoming dive. So we began the dive and started working our way down a deep vertical wall that ran parallel to the shoreline. This was the northern side of the wall, so there is no direct sunlight here except in summer, so it was fairly dark and lights were on as soon as we went over the edge.
On our way down we encountered the opening to a large shallow cavern. Since things were apparently going well and my buddy seemed comfortable enough, we entered the cavern and had a look around. We reached the back of the cavern within minutes and decided that further poking around could wait until another time since we had not planned for or equiped ourselves for overhead diving.
We exited the cavern and continued the dive along the wall, but we didn't realize that we were still under a rock ledge about 50' above us, well beyond the range of visibility in this water, which rarely exceeds 20'. We continued on until it was time to begin our ascent and started on up.
When we reached a depth of about 35', my buddy's ffm began free-flowing violently and flooding. He started pointing at the top of the mask where the bubbles were streaming out and began pulling on the skirt of his hood. I would learn later that he thought the hood skirt must have gotten under his mask skirt and broken the seal, but I never saw any indication that it had. In any event, the bubbles kept streaming and the water kept pouring in.
He got choked. He fought with the mask, trying to get his head into a position where his mouth was out of the water but it was no use. Instead of shedding the mask and going to his backup reg, the cold water in his face and the inability to breathe made him bolt for the surface. I reached out to grab him but he was just out of reach. He didn't get far though, because he slammed into that rock ledge we hadn't seen with enough force that I was sure it had knocked him out. He was still moving around and immediately resumed his efforts to get to the surface. The delay bought me enough time to get my hands on him and I think I managed to help him get out from under the ledge and slowed his ascent somewhat. There was no use at that point trying anything else because he was firmly in the grip of "gottagetthehellouttaherenowwwww" mode, so I focused on just trying to keep him from embolizing. It was all the help I could offer.
Once he hit the surface he ripped the mask off and began gasping for air, and I helped him get buoyant enough to keep his head out of the water. He calmed himself, apologized for the episode, and began working on finding the cause.
We determined later that the incident was caused by a maladjusted strap assembly. The mask started to leak a little, and as he kept pulling the straps tighter it just made things worse because the straps were literally pulling the mask up off his face. We readjusted the strap assembly and conducted another dive without incident, after a sufficient surface interval to calm down and sort things out of course.
What would have happened if this had occured deep inside the cavern? Would I have been able to get control of him and get him some air? Would he have sorted it out on his own, knowing that a bolt for the surface wasn't an option? Or would he have totally succumbed to the grip of panic and repeatedly bashed his head into the ceiling until he lost consciousness? I don't know. But the lesson I learned was that if you are ever "working the kinks out of" a new piece of life support equipment, working it out in open water first can save your life!
He felt comfortable enough to take it into deep open water in order to simulate the cold temperatures we would encounter underground on our upcoming dive. So we began the dive and started working our way down a deep vertical wall that ran parallel to the shoreline. This was the northern side of the wall, so there is no direct sunlight here except in summer, so it was fairly dark and lights were on as soon as we went over the edge.
On our way down we encountered the opening to a large shallow cavern. Since things were apparently going well and my buddy seemed comfortable enough, we entered the cavern and had a look around. We reached the back of the cavern within minutes and decided that further poking around could wait until another time since we had not planned for or equiped ourselves for overhead diving.
We exited the cavern and continued the dive along the wall, but we didn't realize that we were still under a rock ledge about 50' above us, well beyond the range of visibility in this water, which rarely exceeds 20'. We continued on until it was time to begin our ascent and started on up.
When we reached a depth of about 35', my buddy's ffm began free-flowing violently and flooding. He started pointing at the top of the mask where the bubbles were streaming out and began pulling on the skirt of his hood. I would learn later that he thought the hood skirt must have gotten under his mask skirt and broken the seal, but I never saw any indication that it had. In any event, the bubbles kept streaming and the water kept pouring in.
He got choked. He fought with the mask, trying to get his head into a position where his mouth was out of the water but it was no use. Instead of shedding the mask and going to his backup reg, the cold water in his face and the inability to breathe made him bolt for the surface. I reached out to grab him but he was just out of reach. He didn't get far though, because he slammed into that rock ledge we hadn't seen with enough force that I was sure it had knocked him out. He was still moving around and immediately resumed his efforts to get to the surface. The delay bought me enough time to get my hands on him and I think I managed to help him get out from under the ledge and slowed his ascent somewhat. There was no use at that point trying anything else because he was firmly in the grip of "gottagetthehellouttaherenowwwww" mode, so I focused on just trying to keep him from embolizing. It was all the help I could offer.
Once he hit the surface he ripped the mask off and began gasping for air, and I helped him get buoyant enough to keep his head out of the water. He calmed himself, apologized for the episode, and began working on finding the cause.
We determined later that the incident was caused by a maladjusted strap assembly. The mask started to leak a little, and as he kept pulling the straps tighter it just made things worse because the straps were literally pulling the mask up off his face. We readjusted the strap assembly and conducted another dive without incident, after a sufficient surface interval to calm down and sort things out of course.
What would have happened if this had occured deep inside the cavern? Would I have been able to get control of him and get him some air? Would he have sorted it out on his own, knowing that a bolt for the surface wasn't an option? Or would he have totally succumbed to the grip of panic and repeatedly bashed his head into the ceiling until he lost consciousness? I don't know. But the lesson I learned was that if you are ever "working the kinks out of" a new piece of life support equipment, working it out in open water first can save your life!