Well that was stupid ... complacency strikes

[HalcyonDaze]

It's funny since I got out of it, but this really, really, really would have been an embarrassing way to check out on Dive # 700-something after a good 14 years. I've decided to post this to show that even an "experienced" diver can make a very basic mistake through sheer complacency.

Some time ago I went on a dive charter with a friend. We rented nitrox tanks from the boat at the dock and loaded them aboard; when we settled into our spots there was a fifth tank next to us in the racks (I'm not sure if it was between ours or at the end) that was presumably left over from the morning dive. One of the DM's came through and checked the O2 mixes on all five tanks while we watched the readouts, and off we went. First dive, no issues.

On the surface interval, we switched over tanks. One of my buddy's tanks had a bad o-ring, so rather than changing it out I told her to take the next tank over and I bumped down to the next tank in line. This is where I made my big mistake; I put my BC on the tank, hooked up my reg, turned it on, and did not check my pressure gauge. Not right after I changed the tank over, not as I was gearing up for the next dive, not before I got in the water. I just turned the tank on and jumped into 75-80 ft of water with the expectation that everything was in order.

Welp, about 15 minutes in at a depth of 75 ft I notice my reg is breathing a little hard. At this point I decide while I shouldn't be having air issues, I'll look at my gauge. Now, since I wear a wrist computer I just have a bare SPG on the end of my high-pressure hose, and when it's under pressure the swivel on the gauge is very stiff. When I grabbed it this time, the gauge spun freely in my hand. That was my second hint I was screwed.

My third hint was when I looked at the gauge. Zero. Zip. Nada. ****!

Now, I was fortunate at this point that my friend was a) someone I hadn't dove with before, b) someone I was taking on a checkout trip for a more demanding dive two weeks later, and c) really knew her stuff. So first off I actually had a buddy I was sticking to like molasses (something that's become less and less frequent in recent years) and second that person knew what to do when I swam over and showed her a flatlined gauge. I never actually pulled a Coke bottle on the tank, but after getting about 10 ft off the bottom I signaled to start a shared air ascent. There were no further problems, we took the time for a three-minute safety stop, and overall it was a very cool, calm, and collected affair. Needless to say, I paid for her dive trip after we got back to the dock - the "save your buddy, get a free dive trip" rule.

Afterwards, I tested my reg on the tank from the first dive (600 psi) and the one with the dodgy o-ring (3000+ psi). So in hindsight, what must have happened was that one of those five tanks was probably drained down to about 1000 psi or so at the time we left the dock. As stated, I'm not sure whether that tank was one of the ones we drew out of the equipment shed at the dock or the "spare" left over from the morning dives; however the end responsibility was mine to make sure the damn thing had gas in it before I jumped off the boat. I blew that responsibility off because I had gotten complacent; I assumed everything was in perfect order for a dive that in my book was something of a milk run. If I hadn't been sticking close to a buddy, I would have been profoundly ****ed with nobody to blame for it but myself.

Mark my words, I'm never doing that again.

 

[AfterDark]

Survive and learn. Glad you did. Dive long enough and something simple but stupid will happen that will either nudge a diver awake or end their diving. This is why I don’t dive with an octopus or safe second stage as it’s called these days. A safe second stage connected to an empty tank ain’t so safe.

I dive with a pony when buddy diving and ID’s when solo diving. Alternate air, I don’t leave the beach or boat without; fail safe.

You might want to get the spool valve in the SPG looked at.

 

[tursiops]

Survive and learn. Glad you did. Dive long enough and something simple but stupid will happen that will either nudge a diver awake or end their diving. This is why I don’t dive with an octopus or safe second stage as it’s called these days. A safe second stage connected to an empty tank ain’t so safe.

I dive with a pony when buddy diving and ID’s when solo diving. Alternate air, I don’t leave the beach or boat without; fail safe.

You might want to get the spool valve in the SPG looked at.

I do not understand your comment. Sure, an octopus attached to an empty tank is of no value; but a primary attached to an empty tank is also of no value. So how do you conclude that an octopus is a bad idea? Seems like the problem is not the octopus, the problem is the empty tank.

Also, why do you suggest to look at the spool?

 

[AfterDark]

I do not understand your comment. Sure, an octopus attached to an empty tank is of no value; but a primary attached to an empty tank is also of no value. So how do you conclude that an octopus is a bad idea? Seems like the problem is not the octopus, the problem is the empty tank.

Also, why do you suggest to look at the spool?

Sounds like you understand very well. What good is an empty tank you asked. So why have a 2nd second stage if there is a possibility no matter how remote that both could be connected to an empty tank at some point during the dive? My preference is to have an alternate air source at the end of my 2nd second stage. I'm a big believer in coming back to surface safe and sound and knowing I am far from perfect an alternate air source is one of the many things I do to help make that happen. It is after all my life, my dive so I get to make the calls. After 46 years of diving and coming back safe everytime I'll stick to my winning formula.

Both my SPG's rotate with the same resistance under pressure or not, my thought is something my be amiss with the OP's spool if the resistance is different depending on the pressure in the tank.

 

[RyanT]

Thanks for sharing. I had a similar experience many years ago. I was diving a LOB where you bring one tank and they refill it for you after each dive. The procedure was that after your dive, you unhook your regulator from the valve. When the crew refills your tank, they replace the regulator and you know your tank is full. Apparently someone replaced my regulator without refilling my tank. The next morning my buddy was ahead of me getting in the water. So in a hurry, I threw my rig on and splashed (without checking my spg) to find him. I had drained my tank low the previous day, so at around 50' I noticed my reg was getting harder to breathe. I figured I must not have opened the valve all the way. I checked my spg, expecting the needled to swing down during inhalation. It didn't, it just read empty. I could not wrap my head around this, I kept thinking that my tank had to have gas in it. So I see my buddy down at around 70'. I continued to drop down to him. When I reached him, there was nothing left in my tank and I was truly out of air. I still thought, I must have only barely cracked my valve. I gave him the OOA sign and asked him to check my valve. He did and indicated it was open. At this point my eyes were starting to bug, so I slashed again and he gave me his alternate and we ascended. So while one of the dive crew did make a mistake, ultimately it was my responsibility to check and this was another incidence of complacency creating a problem.

One of the big learning moments from this incident was the fact that I kept convincing myself that the problem was not what it was. Because someone had replaced my regulator, I just had it in my head that I couldn't be out of gas, and I was searching for alternatives to what the problem actually was. It was a big lesson. The moment I saw my needle not swinging upon inhalation, I should have recognized then that I was really out of gas.

 

[rongoodman]

Thanks for sharing. I had a similar experience many years ago. I was diving a LOB where you bring one tank and they refill it for you after each dive. The procedure was that after your dive, you unhook your regulator from the valve. When the crew refills your tank, they replace the regulator and you know your tank is full.

So where in this process do you analyze your gas? Every LOB I've been on has the crew replacing the plastic cap after filling, not the regulator.

 

[RyanT]

@rongoodman: This was in the early 90s and we were all diving air, so we were not analyzing our gas.

 

[yle]

So where in this process do you analyze your gas? Every LOB I've been on has the crew replacing the plastic cap after filling, not the regulator.

Doesn't sound like they were filling tanks on board. There were 5 tanks to start, and apparently only 4 were full. But it's very likely all 5 had caps on to start (or there were no caps on any of the tanks... some shops don't use caps.)

I had the same thought about analyzing; if all tanks were analyzed, they should have had labels and the divers shouldn't have been switching tanks. But the OP didn't address this.

 

[HalcyonDaze]

To clarify, the setup was that the rental tanks were stored in a shed at the dock and we carried them on the boat with us. The O2 analysis on the boat prior to departure was done using a simple handheld unit, so the only pressure check would have been once I had the reg hooked up. All the tanks had 32-33% mixes in them and were labeled after the analysis.

If I had to guess, the most likely scenario would be that on the morning dive, someone used that "extra" tank and put the dust cap back on. When the switchout took place for the afternoon dive, the tank wasn't removed from the boat because it appeared full. Regardless, as stated it was my ultimate responsibility to make that check and I goofed; I didn't point fingers at others then and I won't now.

As far as having an octopus versus a backup tank, I see a pony bottle as useful, but more as insurance against a catastrophic failure of the first stage, HP hose failure, or just being stupid enough to overstay one's limits at depth. Jumping off the boat with a partially full tank is more a failure of the three pounds of gray Jell-o upstairs. I'm definitely looking into getting a pony bottle though, as in recent years I've done a fair amount of solo or "S.O.B." diving at the deep end of recreational depths without a redundant air source. I also made moves to acquire my own tanks afterwards - something I resisted doing because doing a lot of recreational diving is something I really only started about four years ago and in the decade prior to that I had bounced through four states in opposite corners of the country, which does not encourage purchasing heavy objects.

As far as the swivel, not sure if there's an issue there - I use my rig for work, so I'm required to take it in for annual maintenance. The current HP hose and swivel was a replacement installed about 2 1/2 years ago and it hasn't been an issue.

 

[EricTheDood]

Thanks for sharing.

However, this isn't a complacency problem. This is a problem of bad habits, or lack of good ones.

Complacency would describe a diver pushing his air reserve limits as he gets more comfortable in the water, or always pushing NDL limits (or even exceeding them).

Not checking an SPG before jumping in? If this was a one-time deal, then it was a brain-fart. If this is a regular thing, then it was Russian Roulette.