Gear-Related Incidents

The sun was out, and the visibility down at 30 feet was excellent. It was nearly time to ascend, so my buddy tapped her watch and then gave me the "OK" signal; I happily signaled back. This down time was just what I had needed after a busy week at work.

Then, just when everything was going perfectly, I heard some bubbling. I removed my second stage from my mouth and held it with the mouthpiece facing downward. To my dismay, I saw bubbles coming out — my regulator was leaking. We were almost at our safety stop, so I put the regulator back in my mouth and double-checked that my buddy was within reach in case something unexpected happened. Thinking about it, I realized I hadn't had my regulator serviced since last summer, so I resolved to drop it off at the dive shop later in the week. Better safe than sorry when it comes to having gas to breathe.

Take two breaths from your regulator on the surface while watching your gauge.
When I got back to work at DAN®, my first task for the week was to look at the latest diving incident reports, which are submitted by divers who have had or have witnessed a near-miss. These are unexpected events that could have resulted in an injury. Curious, I counted how many of the incidents were the result of equipment malfunctions. Of the first 92 reports I reviewed, 16 incidents (17 percent) involved equipment issues. Based on other data, we know this number likely overrepresents the incidence of equipment problems, but this overrepresentation stands to reason because equipment failure is a matter of concern to many divers. I found it interesting that 13 of the 16 equipment problems reported (81 percent) related to air supply, and the other three reports (19 percent) related to buoyancy control.

While studying the air-supply problems, I soon identified a common error: failure to watch the submersible pressure gauge (SPG) while test-breathing the regulator. Here is an excerpt from one of the incident reports:

The group went out with four divers and two guides. The drop-in was a back roll, and I dropped in first. Prior to entry I checked all my gear and tested my regulator and inflator. I then dumped the air from my BCD [buoyancy control device] and moved into position. The deckhand checked all my equipment and made sure my tank valve was opened. I rolled in and dropped down 6-10 feet and took my first breath: nothing. Now I was underwater, slightly negatively buoyant, with no air for breathing or inflation. I kicked for all I had and was able to reach the boat and grab ahold of the swim deck. The deckhand was then able to reach over and turn my air back on.

Make sure your tank valve is always either fully open or fully closed.
Another incident report highlights a common error that's reported to DAN every year: turning the valve the wrong way.

While diving in Florida, I noticed that upon each inhalation the needle of my SPG fluctuated. It dipped down with each breath before returning to the correct pressure reading for my tank. I continued diving while keeping a close eye on the gauge, and upon reaching a depth of approximately 55 feet it suddenly became very difficult for me to breathe. I looked at my SPG mid-breath and saw the needle drop to 0 psi, and it did not readily move back up. I felt like there was no more air available to me even though I knew there was at least 1,200 psi in my tank. I signaled "out of air" to my buddy and used her alternate regulator. We made a controlled ascent to the surface, and I was not injured. Upon inspecting my gear I realized that instead of turning on my tank all the way and then half a turn back, I had turned it all the way off and half a turn on. Upon descending below 33 feet I experienced inadequate air-pressure delivery from my tank to my regulator because the tank was barely on and could not continue to deliver the same volume of air at the increased ambient pressure.

Test your power inflator before entering the water.
Together these two incidents highlight how to avoid most gas-supply problems. First, make sure your valve is all the way open or all the way closed. The days when divers needed to turn the valve back a quarter turn are long behind us. Second, and this is essential for diving safety, every diver should look at his or her SPG while taking two breaths just before entering the water. If your tank is turned off or you are wearing an empty tank, then as long as your valve is all the way open or all the way closed you will be able to tell if you are good to go by taking a couple of test breaths. If the needle drops, then your valve is closed, but if it stays still in the full zone, then you should have adequate gas supply to enter the water.

Buoyancy problems, although not reported to DAN as frequently as gas-supply problems, may still be common. Most are easily avoided by following these three simple tips:

  • Always test your power inflator before you enter the water. If it is going to stick, then this is when it is most likely to do so.

  • Always check that you can orally inflate your BCD before entering the water in case you need to do so in an emergency.

  • Look at your weight-removal system. If you are using unfamiliar equipment, make sure you know how to drop your weights, if needed. If you are shore diving on a calm day, consider a quick weight drop while floating on the surface in 4 feet of water.

Keep in mind these few simple tips to prevent the equipment problems most commonly reported to DAN: Make sure your tank valve is fully open or closed, and familiarize yourself with your BCD and weight-removal system before diving with them. By following these suggestions, you can avoid many rare but potentially serious equipment problems.
For More Information
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© Alert Diver — Q2 Spring 2016