I attribute the fact that I am here today to write this to my instructors, from Basic through Dive Master. During the Labor Day weekend I had my first serious out of air incident on a deep dive. I could have killed myself with less training as well as my buddy. However, I remained calm and took steps to perform a self rescue. I am writing this to share my incident with you as well as the cause.
It was a perfect dive day not too hot with plenty of sun. My buddy, his wife and I were on a dive boat off Catalina Island, California. The first dive site selected for the day was a location called Little Farnsworth Bank. This is a spectacular dive with large reef outcroppings packed with life. This was selected because of itís depth of 130 feet.
I consider myself a good, safe and fairly knowledgeable diver having completed NAUI and LA County Basic and NAUI Advance and Rescue. Now, I am currently in a PADI Dive Master program and I plan to go on to become an Instructor. My buddy has the same training and goals in mind and this makes us a good buddy match. We beach dive just about every Sunday along the coast of Southern California from Point Dume to Point Conception. We are quite good in adverse conditions such as current, surge and low visibility as well as navigation.
Since we do most of our diving off a beach through the waves, a boat dive is much more enjoyable. It is a chance for some very relaxing dives with good bottom times. This day, however, would prove to be the scariest of my life.
After checking each others equipment out we entered the water one at time. My buddy and his wife went through the gate off the side of the boat. I went off the swim step. We met at the bow anchor line and agreed to meet at the anchor on the bottom. At this point I will tell you that we did have an agreed upon dive plan. It was that my buddy would lead with his wife while I tagged along.
The conditions underwater at the anchor were very good, no current, no surge and 50 feet plus visibility. When we were all together at the anchor at 122 feet we again checked our gear and looked at each others submersible pressure gauges (SPG). It was determined that I had the least amount of air at 2750 PSI. My buddy signaled and we were off on his tour since he has done the dive three times before.
I have always been one to worry about my air supply to the point that on some dives I check it about every one to three minutes. This dive was no exception since it was a deep dive for me. Normally, I dive off the beach at 25 to 40 feet. One of the first things I purchased, in addition to the basic dive gear, was a 3000 PSI Spare Air. Being somewhat of a mechanical engineer, I know that regardless of all the best maintenance, sometimes things just stop working. The Spare Air 3000 offered a cost effective, independent air source. I would never dive without it.
After having had an encounter with two very large sea bass, about 150 to 200 lbs. each I was swimming inverted, enjoying the abundant life within the rocks. Without warning my air was suddenly reduced to less than one quarter of a breath. Receiving very little air I determined my regulator had just failed. I changed to my octopus and found that it too was not delivering the needed air. While trying to draw the first breath out of my octopus I was viewing my SPG. It was now obvious that the problem lie not with the regulators but with my first stage. When I drew a breath the needle would move from 1950 to 0 before I received half a breath. This was a problem! I was now the closest to total panic that I have ever been. I thought of my wife, kids and my parents. I then realized that panic would definitely kill me. I needed to solve this problem now.
My buddy was with his wife about fifteen feet in front of me and they were both looking the other way. Taking very little time to evaluate my options, I knew three things at this point. One, I needed to get air very soon. Two, I needed to get to the surface properly. Three, I had my spare air if the air quit completely. I swam quickly up to my buddy while breathing very shallow and knowing I could not keep this up for long.
When I reached my buddy I quickly got his attention and had him watch my SPG as I tried to breathe. His face was confused. Later, I learned he thought I was having a problem with my gauge since it had acted up a few weeks earlier. It had been repaired which he did not know. I was not about to hang around at one hundred feet to try to communicate with him. For some reason I was not ready to buddy breathe. I wanted to solve this problem without endangering someone else if I could. I have practiced several times with my Spare Air in similar conditions. I was reassuring myself that I could rely on my Spare Air, if needed. By now about one minute had passed and my need for a full breath was steadily increasing.
I made the decision to abort the dive and head directly for the surface as fast as I could. I started swimming straight for the anchor line, it was about twenty five feet away. I could see my buddy and his wife and they were heading my way. I knew that help was right behind me if needed. I started up the line as fast as my computer would let me. When I reached about forty five feet the tank started to deliver a little less air. At about twenty five feet the tank continued to deliver the same amount of air, just barely enough. When watching my SPG the needle would go from 1650 or so to zero before I could get half a breath. I was now concentrating on relaxing as much as possible to conserve the air I was getting.
I continued up the anchor line until I reached fifteen feet where I stopped. At this point the air being supplied was still barely half a breath. Forcing myself to remain calm, I did a three minute decompression stop. When I broke the surface I immediately spit the regulator out and took the best and longest breath of my life.
As soon as I got on the boat I informed the crew of what just happened and started to inspect my equipment. Upon removing the first stage the problem became evident. Packed in my first stage filter was what looked like white flaky powder. The crew of the dive boat and I all concluded that this white powder was corrosion from the inside of the aluminum tank. We additionally determined that possibly the small spout that hangs inside the tank to prevent debris from entering the tank was missing. We then drained some air out of the tank through a dark cloth and found that the white powder was in fact coming out of the tank when inverted. I later noticed that all the tanks on this boat had no visual inspection stickers.
I consider myself not lucky but very well trained. I thank all of my instructors NAUI, LA County and PADI alike for training me properly. In conclusion, I will be very cautious of rental tanks in the future unless I know the source and maintenance history.
Robert A Moriarity