Accident on Southern Cal Oil Rigs Dive

[KevinNM]

I went diving on my pony once. I had no problems, but realized that this could have been very bad. It's easy to do if they are similar second stages and both back mounted.

 

[CuzzA]

Bill Powers, has written all the members of Power Scuba the following with regards to this tragic death. I have copied it here in it's entirety. We rarely get to learn much about the accidents we read about, and this one has a powerful lesson for those who are willing to learn. DO NOT use this as an excuse for blame-storming. If you want more info like this, keep it polite and LEARN.

"When the dive community loses a fellow member, one of the oft asked questions is, “why?”... or, “How could this have happened?”. Rarely do we get a satisfying answer. Closure is what we seek, but it’s sometimes very hard to come by in our sport.

Today, though, we have a fairly concrete answer as to why we lost our friend and fellow diver, Henry Cook, last November. Steel yourself because it’s not going to be easy to digest or accept. Please understand I’m not going to write anything resembling a full incident report here nor will I share all the details known to me. Instead my hope is to 1)Give a margin of closure to those who knew and loved Hank and 2)Provide a few emphatic lessons learned for those of us who continue on. I think Hank would approve.

Remember that Hank was lost during an oil rigs trip aboard a dive charter out of San Pedro. Third dive of the day, the first two having been on the Olympic wreck and Ellen/Elly oil rig complex respectively. On the third dive on the oil rig, Hank expressed his desire to “go a bit deeper” in order to get some of the larger scallops. (Scallops tend to get bigger the further down one goes simply because fewer divers venture to the deeper regions of sport depth.)

Approximately nine minutes into the dive, at depths between 110 - 133 fsw, as they were shucking scallops in-place on the support pylons, Hank’s partner looked over the few feet to Hank... and Hank was limp, rapidly descending tank-first, reg out of his mouth. The partner chased Hank down quite deeply, but was unable to arrest Hank’s rapid decent and was forced to make for the surface himself once 167 fsw was reached.

I don’t even know how to lead up to this next part, so I’m just going to say it: Although he had a steel 100 (29.7% Nitrox) on his back, Hank ran out of air at the nine minute mark because, at the beginning of his dive, he mistakenly put the regulator from his bailout 19 cu ft cylinder into his mouth instead of the reg attached to his primary 100 tank. He unknowingly breathed the entire dive off his much smaller bailout bottle. Upon postmortem analysis, his main 100 tank was virtually full. (Just a tiny amount gone that would’ve been necessary for him to add air to his drysuit on the way to depth.)

Although there wasn’t enough air in the 19 to analyze, it was marked as having 32% Nitrox, which would have put Hank well past his MOD during the harvesting portion of his dive. Whether an O2 toxicity hit played any part in the incident will forever be unknown, but one statement in a report shares that Hank was seen “shaking” on the way down.

Although Hank was also revealed to have coronary artery disease, the medical examiner stated that most likely played no part in the incident.

As I read the investigative report, I found myself saddened and horrified all over again. If ever there was a dive fatality that didn’t need to happen it was this one.
I’m going to end this post with a few lessons learned, because I do think it’s what Hank would want... some type of good to come out of this tragedy. Here’s my takeaway:

1. The pre-dive safety/buddy check is essential and mandatory. One was not accomplished in this instance. There’s actually a picture of Hank as he was getting ready to giant-stride off the boat. He’s clearly shown with his bailout reg in his mouth. His dangling primary reg could’ve been a glaring giveaway during a thorough buddy-check. --- (I wish I could say this is the only time I’ve heard of something like this, but it happened in our group several years ago at San Clemente. Experienced diver & photographer goes solo diving at night... only to discover 15 minutes into the dive he’s out of air because he’d been mistakenly, unknowingly breathing off his pony.)
2. Bailout/pony regs (as well as “alternate” or secondary regs) should be brightly, obviously marked (most times with obnoxious colors like neon green, yellow, or orange) not just for your partner to see, but in order for you to see what you’re putting into your mouth.
3. Bailout/emergency cylinders (vs deco tanks) must NEVER contain a Nitrox mixture greater that that which you’re using in your primary tank... and usually must contain air (21%). This ought to be discovered during a thorough buddy check as well.
4. Your deepest dive of the day should be your first dive, not your last. Scallops aren’t worth it.
5. Do not exceed the Maximum Operating Depth (MOD) of the gas you’re breathing. (Know someone who brags about routinely diving at 1.6 partial pressure or beyond? They are not your friend and care not for your safety.)
6. Most importantly of all: Realize how quickly a drowning can occur. 15-25 seconds is all it takes. Add to that a sizeable water depth and it’s easy to see how rapidly bad things can happen... even if you’re sticking close to your buddy. It then behooves us to be even more attentive to our buddies. Our safety postures must be increased.

As I said above, I’ve purposefully left out details as it’s not my intention to give a full accident report here. Our hearts continue to go out to Hank’s family and friends. Don’t let his passing be for naught. Adopt a more safety-conscious posture right here and now.


Bill Powers
President, Power Scuba, a 501(c)(3) non-profit org
www.powerscuba.org"​

That is a very unfortunate update. One we've heard before. I agree with everything Mr. Powers stated with the exception of unequivocally not diving at 1.6 ppo2. Nevertheless, visually differentiating your primary reg from your pony is absolutely critical. Attached is a picture of the yellow mouth piece on my pony reg. Not to mention I necklace that reg. There is simply no way I could mistake the two regulators. My pony bottles also have vindicator knobs.

Cheap risk mitigation. $3.50... Standard Neon Yellow Long Bite Regulator Silicone Mouthpiece

 

[Marie13]

Since I took old pony reg to be part of SM regs, I put my old yellow octo second stage onto pony. Just using what I had, but it really makes sense after reading the accident update.

 

[johndiver999]

I find it unlikely that using 32% for 9 minutes at 130 ft is going to cause someone to pass out. Possible, but unlikely.

Was the pony bottle worn as a stage bottle or mounted on the main tank? The position of the tank would seem to be relevant in the chance of getting the regulators mixed up.

What is the basis for demanding that a pony contain air not nitrox? I can see where it would make things safer if diving in depths that could possibly exceed the nitrox depth limits, but that is not common to all dive sites. What's so bad about a pony with nitrox that it should never be used?

 

[CuzzA]

Ask yourself this. What benefit is there to putting nitrox in a pony bottle?

 

[boulderjohn]

I find it unlikely that using 32% for 9 minutes at 130 ft is going to cause someone to pass out. Possible, but unlikely.

I would say very highly unlikely--to the point that I would very nearly discount it.

What is the basis for demanding that a pony contain air not nitrox?

The general thinking on a pony is that if it is to be an emergency resource, it should be breathable at the deepest depth to which it might be needed. There is no reason that it could not be a suitable blend of nitrox, but some people choose to have a different philosophy.

 

[boulderjohn]

Ask yourself this. What benefit is there to putting nitrox in a pony bottle?

I am not going to speak for pny bottle users in general--I don't use one myself--but there would be a minor benefit with a nitrox blend in the case of a diver going out of air and needing the pony. If a diver were to get into such a fix, that diver would likely be at or beyond NDLs, in which case the lower nitrogen percentage would have a benefit upon ascent.

 

[CuzzA]

I suppose, but if you're matching your MOD with the dive how much nitrogen are you really cleaning up? For example a planned dive to 130 ft. at 1.4 ppo2 is what, 28%. Is that extra 7% going to make that much of a difference for the ascent and safety stop? Not trying to be argumentative. Honest question.

Edit to add: Personally, I'd rather not have to think about what is in the pony. I also don't want to be constantly dumping and adding gas for different dives. Fill it with air and forget about it.

 

[johndiver999]

Those are reasonable reasons for using air, but they don't seem so serious or essential that they constitute a justification for someone saying "NEVER use anything but air".

"Don't jump in the water with a tank filled with something you can't use in an any emergency" makes sense (if you are not a technical diver), but the admonishment to NEVER put anything but air in a pony seems to providing a simplistic rule that is not applicable everywhere - and probably entirely irrelevant to the accident which occurred. So that is why I raised the issue.

What if your (air) pony leaks down between dives? Is it better to top it off with an equalizer hose with a little nitrox or add no more gas if no compressed air is available on site - might be an example where using nitrox could make sense.

 

[raftingtigger]

Those are reasonable reasons for using air, but they don't seem so serious or essential that they constitute a justification for someone saying "NEVER use anything but air".

"Don't jump in the water with a tank filled with something you can't use in an any emergency" makes sense (if you are not a technical diver), but the admonishment to NEVER put anything but air in a pony seems to providing a simplistic rule that is not applicable everywhere - and probably entirely irrelevant to the accident which occurred. So that is why I raised the issue.

What if your (air) pony leaks down between dives? Is it better to top it off with an equalizer hose with a little nitrox or add no more gas if no compressed air is available on site - might be an example where using nitrox could make sense.

Johndiver999. You are thinking, and taking into consideration the dive and circumstances. I agree with your thinking. That said, in my case I don't want to have to think about what is in my pony (except test for CO), and want it usable at any depth. Mine always contain air as a result. Of course I reserve the right to change that for a specific dive.