The day was all about practice and preparation. Joseph, Natalie and Phil were making a deep dive in their local quarry where the water was cold on the surface and even colder at depth. They were making practice dives for an upcoming trip, and wanted to go deep and experience near-freezing temperatures. They briefly touched 120 feet of fresh water and began making their ascent.

Right then, Phil’s regulator began to free-flow. Through the gloom he signaled to his two buddies that he had a problem. Joseph offered him his alternate air source regulator, but Phil headed to Natalie for help. The two divers began buddy breathing and ascending, but they weren't prepared for what came next.

The Divers

The three divers in this case were all experienced and had no known health problems. Joseph and Natalie were both 43 years old and certified divemasters. Phil was 21 years old and held an advanced open water rating. All three had experience with numerous dives in the same quarry.

The Dive

The three divers met at their local quarry, planning to make a deep dive. They had all dived at this site before, but mostly shallower than 60 feet. All of the divers wanted to go deeper to help prepare their skills for an upcoming trip. They knew it would be cold and dark at depth, but that didn’t matter—they didn’t plan to stay there for long but wanted to feel the cold so they would know what to expect later.

The air temperature measured in the lower 60s, and the surface water temperature was about the same. They knew the temperature dropped off about 10 ­degrees below the first thermocline and got even colder the deeper they went.

The divers made a shore entry into the quarry and swam out to a buoy floating on the surface. They followed the descent line to a platform at 70 feet. Once they arrived and checked on each other, the divers followed another line that took them to a deeper part of the ­quarry. They began that secondary descent, reaching the bottom a few minutes later at 120 feet. The water temperature had dipped to nearly 45°F, and they could barely see each other even with the lights they were carrying. The group headed for the ­surface having achieved its goal.

They paused for a moment at 100 feet when Phil signaled he had a problem.

The Accident

Phil was surprised when his regulator began free-flowing. He immediately showed the problem to his two dive buddies. ­Joseph pulled his alternate air source regulator loose from the holder on his BC and offered it to Phil. Instead, Phil moved toward Natalie, and she gave him her ­alternate air source. Then her own primary regulator began free-flowing as well. Phil and Natalie began buddy breathing, and headed for the surface. Joseph did his best to ascend with them, but he lost sight of them while he ascended.

Just after he made it to the surface, Joseph looked around. He saw two divers from a different group reacting to a problem. It was Natalie and she was unconscious. They were towing her to the beach. Joseph began yelling that there was another diver in trouble, and he ­began swimming for the shore.

Phil’s body was recovered an hour later. Both divers' tanks were empty. Their autopsies showed physical changes consistent with drowning. Phil’s autopsy also showed air bubbles in both sides of his heart and in his cerebral blood vessels, consistent with an arterial gas embolism.

As a precaution, Joseph was treated at a local hyperbaric chamber. He wasn’t showing obvious signs of decompression illness, but because of the situation and his own rapid ascent, the doctors determined it was a good idea just to be safe.

Analysis

Diving-equipment failures are extremely rare occurrences. When they do arise, it is more likely a byproduct of poor maintenance than any direct failure from the equipment itself. And then your ­reaction to the problem is the most important ­aspect. If you handle it ­correctly, even an equipment malfunction does not have to prove catastrophic.

The cold-water conditions at depth in the quarry likely contributed to the regulator free-flow problems for both ­divers rather than an equipment failure. ­Simple physics can partly explain the ­problem. As the air pressure in your regulator drops from the first stage to the second, the air itself cools. You’ve ­probably ­noticed this if you’ve ever opened the valve on a tank and let the air rush out. It gets ­colder and will even start to ­condense to water ­vapor on the valve.

Why Do Scuba Diving Regulators Freeze?

Breathing heavily underwater, using the alternate air source to fill a lift bag, putting a lot of air into your BC, hitting the purge button on your regulator, or simply placing additional demands on your regulator under frigid conditions can cause it to malfunction and free-flow. The best way to avoid this is to have your regulators serviced routinely, especially if you know you are going to be diving in cold water. There are special techniques for preparing a reg for ice diving, and for equipment specially designed to withstand the rigors of cold-water diving.

In the heat of the moment, your ­response to a problem is a bigger factor. Many divers do not practice ­emergency skills after they earn their diving certifications. That is a problem. All skills ­become rusty with disuse. We forget the small steps and become uncomfortable. In every class, divers are taught how to breathe through a free-flowing regulator so they can make a normal, safe ascent. But many divers haven’t used that skill since they got their certification card.

You can breathe around the air ­rushing out of your regulator, using your tongue as a water dam and sipping at the air. ­Remember, of course, not to seal the regulator in your mouth; that will force air into your airway. Just hold one bite tab in your mouth and let the other side hang loose. Take cautious breaths and begin heading for the surface or to a buddy. You will be losing your air supply quickly. If you were low on air already, or are a ­distance from the surface, you might need to switch to your buddy’s alternate air source to make it to the surface.

In the case above, Phil’s regulator ­began free-flowing spontaneously. Then, when he moved to Natalie’s regulator, the demands of two divers breathing off one tank and first stage spurred the air coming from the tank to cool more rapidly, sending the second regulator into free-flow. That left them the option of buddy breathing, switching one regulator back and forth between them. This is a skill that is taught at leadership levels but rarely taught at the recreational level any longer. Without regular practice, it is ­difficult to coordinate and perform.

The next time you are hanging in the water for your safety stop, take a few minutes to practice some basic emergency drills. Take off and replace your mask. Lose and recover your ­regulator. Breathe through a (simulated) free-­flowing regulator. Practice breathing from an alternate air source and making an ascent. Warn your buddy so they don’t try to respond to an emergency, but do it often enough that those skills and techniques become second nature. You should be prepared to respond to any emergency like it was just another dive.

Lessons for life

• Practice emergency drills. Do this often enough that you don’t have to think about what to do in case of an emergency—a calm response should come automatically.
• Have equipment serviced by a certified professional. Make sure your gear is ready when you are making dives outside your normal comfort zone.

Read More: Lessons For Life

We're often asked if the Lessons for Life columns are based on real-life events. The answer is yes, they are. The names and locations have been removed or altered to protect identities, but these stories are meant to teach you who to handle a scuba diving emergency by learning from the mistakes other divers have made. Author Eric Douglas takes creative license on occasion for the story, but the events and, often, the communication between divers before the accident are entirely based on incident reports.