Karl was confused. When he checked his air moments before, his gauges read nearly 2,000 psi, but he couldn't get a breath. He took the regulator out of his mouth and shook the second stage hoping to restart the flow. His buddy was nowhere in sight, and as Karl turned toward the opening in the wreck, he switched to his octopus hoping it would work better than his primary. He inhaled, but again got nothing. Instinctively, he went up, ramming his head into the ship's upper deck. Karl fought to stay in control and struggled toward the opening. The edges of his vision began to darken during his mad dash for the surface. Just before he broke through, his oxygen-starved brain shut down--and everything went black.
Karl was an advanced diver with about 50 logged dives and good water skills. He was in his late twenties and in excellent health. Eager to expand his diving experiences, he went for a long weekend of diving to the wrecks of North Carolina.
When Karl's boat arrived at the dive site, the captain was pleased to find excellent visibility and very little current. By Carolina standards, it was an almost perfect dive day. The wreck, a former military vessel turned artificial reef, lay in about 70 feet of water directly below the dive boat. The current and wind were so light that the boat's anchor line hung slack in the water. Karl came on this trip alone, and he buddied up with a local diver who was a frequent customer on this boat. They barely discussed their dive plan before suiting up and descending to the wreck's main deck at about 50 feet, where Karl soon separated from his buddy and blew past the abundant fish and soft coral growth, making a beeline for the large, open hatches and dropping through the deck into the ship's cargo holds. After diving for about 10 minutes, he checked his gauges and was surprised and delighted to see that he still had more than 2,800 psi left in his tank. This was about a third of his normal gas consumption rate, but he just thought he had made a rapid improvement in breathing efficiency and gave himself a pat on the back. Thirty minutes into his dive he felt relaxed; his gauges said he had slightly less than 2,500 psi left in his tank and another half hour of decompression time remaining on his dive computer.
Buoyed by his excellent air consumption, Karl began exploring increasingly smaller spaces, swimming down narrow companionways that ran beside the open areas of the ship and looking into the small rooms that had once housed the ship's crew. Luckily, he made a conscious decision to stay near the wide-open holds as he navigated through the ship because, as he swam down one of these long companionways, Karl's regulator started breathing hard. He glanced at his gauge--it still read 2,000 psi. He pounded the second stage against his hand as he began swimming toward one of the large openings some 30 feet away. Karl was very short of air and on the verge of panic so he switched to his octopus, hoping for a better result--not a sip of air came out. Frantically, he struggled toward the opening. Karl fought hard not to breathe in, and when he instinctively shot upward, he slammed his head into the ship's overhead deck. The pain may have saved him from full-scale panic, as he quickly recovered, made it to the opening and swam most of the way to the surface before losing consciousness.
The captain and mate were both sitting on the transom of the boat as Karl's inert body floated to the surface. Fortunately, they were looking at the right spot at the right time and saw Karl as he broke the surface about 50 yards off the stern. The mate grabbed his fins and mask and dived into the water. The captain scrambled to throw a line into the water. As the mate approached the injured diver, he hooked his arm through the ring buoy at the end of the line and towed it with him. Karl was obviously unconscious. The mate dumped Karl's weights, rolled him onto his back and confirmed that he wasn't breathing. Then he ripped off Karl's mask, orally inflated his BC and tried to force a few breaths of air into his lungs. He secured Karl under his arm, holding onto the life ring while the captain hauled the two divers back to the boat. The rescuers quickly stripped Karl out of his gear while trying to maintain rescue breaths and pull the injured diver onto the boat. As they set up the oxygen tank, Karl started breathing on his own--he soon woke up and immediately became combative. It's unclear if Karl was actually in respiratory arrest or if his breathing was just so shallow that his rescuer could not detect it while in the water, but he didn't inhale any seawater. After settling down, Karl began greedily sucking the oxygen the captain offered. The remaining divers were recalled to the boat, and Karl was transported to a local hospital where he was discharged after a few hours of observation.
A test of Karl's equipment showed that his SPG read approximately 1,800 psi even after it was disconnected from the tank. This was a serious equipment malfunction. If his gauge was malfunctioning before he assembled his gear that day, Karl should have noticed it ahead of time by making a thorough pre-dive safety check of his equipment. If the gauge broke during the dive, the accident would have been very hard to predict. Either way, Karl should have been more aware of his air consumption rate. The drastic change in the amount of air he seemed to use was a dead giveaway that his gear wasn't working properly.
Karl was also in what some instructors refer to as the "live forever zone," the point at which divers start to think they're experienced enough to ignore the rules, but they're not experienced enough to realize the danger of this mindset. These divers usually have between 20 and 100 dives logged, and they make up a significant percentage of the accident statistics. With this mindset, Karl took off by himself, not only putting himself in danger but also putting his buddy at risk as well.
Finally, Karl ignored all the rules he had been taught about going inside overhead environments. He used no guideline, lacked a redundant light source and had to search to find the exit when his trouble started. Karl was lucky. This ship was friendly and did not silt out easily, and its wide-open hatches made it easy for him to find the exit. Once he made it out of the wreck, Karl was also fortunate that his lungs were empty, greatly reducing his risk of an embolism during his uncontrolled ascent to the surface. A combination of extraordinary good luck and the skills of a well trained, fast-acting crew saved Karl from almost certain death.
Lessons for Life
If things look too good to be true, they probably are.
You must check it, monitor it and understand how it's supposed to operate so you can recognize problems.
Every dive plan should include an estimate of how many minutes you can dive with your available air supply. This safety check could save you if your SPG fails.
Splitting up unannounced puts you both at risk.
unless you're properly trained and equipped.