Near miss diving doubles for 2nd time

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

SmpleGreen

Guest
Messages
18
Reaction score
0
SmpleGreen, that's really the point here. In addition to the helpful advice and observations others have made, the fact is, at this point in your diving, you should be well past the point where you walk into a dive shop to rent gear and have them eyeball your frame and hand you a medium (or x-large) wetsuit and 15 (or 30) pounds of lead. You need to understand what you're diving, and you can't just take the attitude that it's OK to rely on someone else to "tell you what you need," even if the gear is all new to you. What is the buoyancy of the exposure protection used? Of the steel tanks and the stage? Of the gas inside of the tanks at the start of the dive? Of the backplate and associated rigging? Of the suit once it's compressed at depth (at 3ATA? 5ATA?)? If the shop you rented from didn't go over this, your instructor most definitely should have, before you ever get in the water with it, and particularly since you've never dived the equipment before.

But in the first instance, and more importantly, the most troubling aspect for me is that (at least as presented in your posts), you yourself never asked these questions of anybody. Of course you won't know the answers, since the equipment is new to you, but these are the same questions you needed to ask in order to properly weight yourself and balance your rig when diving a single tank, and they're ever so much more important now.

I hope you don't feel like you're getting dogpiled here; we're trying to help, but at least some of us feel that some of what we're hearing in this story is very disturbing, and it really seems like you're taking on way too much new stuff (gear, instruction, skills, conditions) at once, and really need to slow down quite a bit. Looking over my logbook, I had about 50 dives in doubles before approaching 90ft, and before putting them on for the first time, I spent a good amount of time researching the equipment and buoyancy characteristics so I could have a ballpark estimate of proper weighting and a basic understanding of the gear I was approaching. While you certainly don't need to take the same approach I did, my impression from what you've presented is that these dives were way too much on the other side of caution and preparedness for comfort.

Gombessa... in terms of taking on way too much new stuff, I think you are absolutely correct. It is clear I got in over my head and need to back off and take this more slowly.

As far as relying on someone to "tell me what I need", I think all education at first is relying on someone else to instruct you in how to perform any task. When I was an open water student, the instructor could have told me that I needed to dive with 6 steel tanks, and I would have believed him. We are all relying on someone else to tell us what we need at first. Someone told you what you need to dive with when you started out as well.

Technical diving is in many ways like starting out as an OW student again. I have no familiarity with backplate and wings, how to set them up, how to dive them, etc. That's why I took the class in the first place. Once I learn those things, then it will be up to me to decide how I want to dive my rig. Until then, I am by definition relying on other people to instruct me in how to figure out what I need.
 

Thalassamania

Diving Polymath
ScubaBoard Supporter
Messages
22,171
Reaction score
2,781
Location
On a large pile of smokin' A'a, the most isolated
# of dives
5000 - ∞
...
The first day we hung out around 30ft and did some skills, including isolation drills with our doubles, ooa diver drills (reg sharing), flooded mask swims, etc. During these drills I made a number of changes to my setup, including renting a pair of ankle weights, as my rig was very heavy and my attitude in the water was for my feet to float up above my tanks. By the end of the day I felt pretty comfortable with the rig in the water, with the one exception of not being able to reach my bottom dump valve because it was being covered by my deco bottle (and the string to the dump valve had been cut short...I guess to prevent entanglement issues).
I would consider dual steel 100s with a wetsuit a potential death trap (others have actually been killed by this configuration). Your instructor should never have let you in the water with that combination of gear.
The next dive was going to be our first to depth, around 90ft max. We made our pre dive plan, which included doing isolation drills at the bottom of the line, followed by practice doing deco stops from depth on the way back.

We descended the line, and at around 40 ft I started to feel the thermocline. By the time I reached 75 ft, I was starting to feel extremely cold, and was questioning whether my rented wetsuit was thick enough for conditions (5/7 mil wetsuit in 39F water). The cold made me hyperventilate slightly, and I slowed down my descent to recover. When I reached 90 ft on the line, I was breathing rather rapidly due to the cold, and when asked for an ok from the instructor, I signaled I needed a minute. I slowed my breathing and recovered my composure, and then gave the ok.
a 5/7 mil wetsuit is not adequate for 39 degree water. A full 7 mil farmer john with attached hood may be barely adequate, but in the that temperature range, if I had to dive wet, I would not consider anything but a full 9 mil farmer john attached hood suit.
The instructor went away from the line to see to the other students, and I stuck on the line for a bit because I was feeling too negatively buoyant. I slowly added air to my wing, but it didn't really seem like anything was happening. When the instructor asked for an ok again, I signaled that I wasn't sure about my wing inflation , and the instructor came over and added a bunch of air to my wing and got me to neutral buoyancy.
Again, what sort of tanks, what sort of suit. Why were you so negative?
At this point I left the line and watched the instructor doing isolation drills with one of the students. As I was floating neutral watching the drills, I realized that my core and extremities were very cold, and my breathing was restricted as a result. Even at rest, I was having a difficult time taking slow controlled breaths. My mask was also flooding intermittently, which wasn't helping with my thermal issues. I signaled to another student that I was having issues, and gave the sign that I wanted to ascend. I then went over the the instructor and did the same. He signaled to wait, as a student was in the middle of an isolation drill. I hung and waited for the drill to finish, which took a minute or two. At this point, the instructor signaled that it was time to go, and I signaled that I could no longer see the downline, which I assumed we would be using to ascend. The instructor pointed in a direction away from the line, for us to follow an incline towards shallower depths. Given my issues, I would have preferred to ascend up the line, but I decided to follow the instructor without objection.
Don't always assume that the instructor is right, in this case you were right and the instructor was clueless.
After ascending upward about 20ft, I started becoming extremely positively buoyant, as all the air that was dumped into my wing at depth began to expand (I was extremely negative at 90). The result was that I started accelerating upwards very rapidly. I tried using my wing dump valve to release air, but it did not seem to be working ( it is likely I didn't have the correct orientation for the dump valve to purge properly... I was facing pretty straight up due to the ankle weights). At the same time, I was rapidly accelerating towards the surface. I realized the if I wasn't able to get my dump to work in 5 seconds or so, I was going to rocket to the surface uncontrollably. I decided to flip head down and swim for the bottom, to arrest my ascent and hopefully get to a depth where the air in the wing would recompress and I could control my buoyancy.
Do a search for my post on creating an "air siphon" this is a technique that could help a lot in a situation such as this.
Upon flipping, enough pressure went to the bottom dump (the one I couldn't reach) that I felt some air release out the back of the wing, and I was able to make downward progress. However, upon flipping over and kicking downwards my mask flooded, and I lost one fin. At this point I was fully hyperventilating and working very hard to keep from aspirating water through my nose. I was more or less singly focused on swimming downward to a depth where I could stop my ascent and attempt to correct my numerous other issues.
You had a bunch of problems ... but you did good. I hope you found your fin.
My instructor caught me around 60 feet, and signaled me for an ok (I didn't see this at the time). I couldn't see anything through my mask, and latched onto him to attempt to stabilize myself and regain breath control; I was more of less fully panicked at this point. Because of my lack of response, he concluded that it would be best to reconnect my inflator hose (apparently it had become undone in the chaos), and inflate my wing to send me to the surface. I was unaware that he was doing this, but did feel myself ascending and was now focused fully on continuing to breathe (the hyperventilation gave me the sensation that I was not getting enough air). I had a tight grip on the instructor, so we both headed to the surface.

We reached the surface, and the instructor asked if I had continued to breathe out during the ascent, to check for possible embolism. I responded that I had been hyperventilating during the ascent (but had not held my breath).
I'm sorry, you instructor needs some remedial training.
I then went on 50% O2 for 10 minutes. I didn't feel any signs of embolism or DCS.
There was no 100% oxygen available? That is a major oversight and liability problem.
I will post later with my lessons learned from this experience, in addition to a few more specific details on what happened (from computer download.... Currently some of this info is reconstructed from info gleaned from instructor, in addition to my own very imperfect recollection. The actual depths at which some of this took place can be filled in when I DL from my computer, in addition to ascent rate specifics, etc).

In the meantime, would be interested in thoughts from the board. I made a number of very serious mistakes on this dive that brought me as close as I've ever come to ending up another quarry statistic. I think given the two fresh postings of quarry accidents on this board (with one confirmed fatality) on the exact same day that this happened (oct 2) make it very I important that these incidents be analyzed for lessons learned.
You handled a difficult situation that you were not prepared for, bravo. Now find an instructor who can organize things and see far enough ahead so that you don't have to continue to learn by cheating death.:shakehead:
I don't blame the instructor ...
You don't have to, I'm happy to do so, this was (after all) A CLASS!
 

parzdiver

Contributor
Messages
10,230
Reaction score
1,651
Location
Lansdale, PA
# of dives
500 - 999
I am taking the TDI tech courses at another shop and the first class we HAD to take was Intro to Tech. Before Advanced Nitrox and Deco procedures, we did two pool sessions with doubles and a drysuit and then six dives in that gear. I had a good number of dives with a drysuit, so was used to that, but another person had those six dives as their only experience with drysuit and doubles. They were "okay" with that, but on the first dive with a deco bottle they were completely uncomfortable and decided thumbed the dive. Their buddy (who was the instructor) immediate ascended with them.

Reading your responses, I think you have learned valuable lessons. One thing I recommend is taking it a little slower. Switching to steel doubles is a HUGE change, since they are so negative. Get comfortable in them before adding the stage bottles.

Good luck and please dive safe.
 

tonka97

Contributor
Messages
795
Reaction score
10
Location
West Virginia; Seattle and SF 20 yrs.
# of dives
I'm a Fish!
The 1st post:
"I tried using my wing dump valve to release air, but it did not seem to be working ( it is likely I didn't have the correct orientation for the dump valve to purge properly... I was facing pretty straight up due to the ankle weights)"

Note that you were trying to release air from the wing with the manual deflator, NOT a dump valve. Dump valves have strings to pull for air release.

You report that you were in a vertical orientation. It is evident that you were not utilizing your manual deflator properly, a very basic error that most of us have committed, at one time or another!
 

TSandM

Missed and loved by many.
Rest in Peace
ScubaBoard Supporter
Messages
36,349
Reaction score
13,639
Location
Woodinville, WA
Reading this story makes me incredibly glad of the training I've had and the way I have done it.

First off, I had classes that honed my buoyancy control and tolerance for task-loading in a single tank, until it was close to the required level for technical diving.

Then I transitioned into doubles -- NOT doubles and a bottle, just doubles -- and dove them until I brought my performance up to the standard I'd already learned in a single tank. That took time, it took finding the right tanks for me, it took figuring out how to weight myself correctly and distribute that weight for ideal balance, and it took spending time in the water until the gear was familiar and comfortable. I did lots of air-sharing and valve drills in shallow water, until they were smooth. THEN I took a couple of non-technical classes to be exposed to failures management and midwater skills and problem-solving, and all of those classes were in familiar sites and with familiar teammates.

THEN I added a bottle, and all the complexity that comes with having three more gas supply sources on a team, with all the failures and issues that come with that.

I don't know you at all, so please do not take this personally. But my first reaction to reading this story was that all of you should step back and reevaluate your underlying diving skill, and whether you are really ready to step up to technical diving. This is why so many of us recommend GUE Fundamentals or an equivalent class for people who are considering tech diving -- you need an objective eye on your basic skill level, before you take on new challenges.

Secondly, the point has already been made that too many things changed at once here. To my way of thinking, your class should have started in a pool or very shallow water, with doubles alone, and should have STAYED there until all team members had an acceptable level of performance with all required skills in the doubles, and that includes precise buoyancy control. My instructors have never had any problem telling us that we just weren't doing well enough to go on to the next step (even when that step involved an already paid-for and expensive charter boat!) because overfacing students is just plain UNSAFE, as you unfortunately learned.

The standard of performance for technical diving isn't the "do the skill once and don't drown doing it" that is all too often accepted for recreational diving. Technical divers need to be able to reproduce their performance RELIABLY, and under stress. I'm not a tech instructor, but I wouldn't have taken a student to 90 feet to do valve drills who had corked doing them the day before. I would have gone back to the shallows until the student could do SEVERAL drills with control, before I took that kind of risk.

I think the story shows a group of inadequately prepared students trying to take on too much at once, and not being helped at all by an instructor with truly questionable judgment. Again, I'm going to say that "it's the instructor" is so very, very true with technical instruction, and I'm very glad that I did all my such instruction from people who learn to teach in a very structured curriculum that has an extremely heavy emphasis on student safety.
 

Gombessa

Contributor
Messages
4,436
Reaction score
225
Location
NorCal
# of dives
200 - 499
As far as relying on someone to "tell me what I need", I think all education at first is relying on someone else to instruct you in how to perform any task. When I was an open water student, the instructor could have told me that I needed to dive with 6 steel tanks, and I would have believed him. We are all relying on someone else to tell us what we need at first. Someone told you what you need to dive with when you started out as well.

Technical diving is in many ways like starting out as an OW student again. I have no familiarity with backplate and wings, how to set them up, how to dive them, etc. That's why I took the class in the first place. Once I learn those things, then it will be up to me to decide how I want to dive my rig. Until then, I am by definition relying on other people to instruct me in how to figure out what I need.

What I'm trying to say is, you have enough dive experience, and you know enough about diving in general, to ask certain questions. The concepts of weighting, buoyancy and thermal protection don't change when you dive a backplate or doubles.

You also know enough to be a proactive student in a technical diving class. It just sounds like your attitude (or perhaps just your preferred learning style) is to accept whatever the instructor says, and assume any omissions or unanswered questions are done because they're irrelevant to bring up in the first place. As you've seen here, that can be problematic. I'm not saying you should pre-learn everything before class, or combatively challenge everything the instructor says, but there are things that only you're aware of (like, I have no idea how this gear works or how much it weighs in the water, or what kind of wetsuit I'm wearing) and it's to your benefit to take an active roll in or before class in figuring it out. You certainly don't know what you don't know, and you can't be faulted for that. But it seems in this case, you didn't use what you DID know, and instead abdicated all responsibility for learning to what your instructor tells you (or doesn't tell you). I know it's coming off as straight criticism, and a bit harsh and condescending, but that's not my intent; instead, I'm just submitting this so that you might consider the approach you take to class and gear research a bit differently in the future.

When I was an open water student, the instructor could have told me that I needed to dive with 6 steel tanks, and I would have believed him.

Sure, when you were just starting OW, an instructor could have handed you a manifolded 6-tank setup and a suit of armor to wear. But I bet you would have thought back to the dozens (hundreds) of images you've seen through the years of people diving in AL80s and wetsuits, and asked what the deal was with this getup. :wink:

Also, this is kind of an aside, but after reading gsk3's post, you did originally mention a DIR gear config. While it's pretty clear you're not in any GUE or UTD class, from what I understand, the gear aspect of DIR is predicated mainly on the idea of team diving; without the team (and associated team training), it make much sense at all (at least to me). If you're looking do solo diving or absolute self-sufficiency, instead of taking a course taught in a hog rig and deciding how you'll change it up later, why not start "on the right foot" and start with the training for the type of diving you expect to do?
 

tonka97

Contributor
Messages
795
Reaction score
10
Location
West Virginia; Seattle and SF 20 yrs.
# of dives
I'm a Fish!
TSandM always provides great posts.

I was surprised that after complementing your own training, TSandM, you add:

"But my first reaction to reading this story was that all of you should step back and reevaluate your underlying diving skill, and whether you are really ready to step up to technical diving."

Do you mean the posters on this thread? Seems like nearly all have been pretty darn appropriate and helpful, and some have come from technical divers. (Thalassamania comes to mind)

I'm not sure of your meaning.

EDIT: Gombessa may have clarified (in the next post) to whom you were referring.
Sorry for misunderstanding.
 

Gombessa

Contributor
Messages
4,436
Reaction score
225
Location
NorCal
# of dives
200 - 499
Do you mean the posters on this thread? Seems like nearly all have been pretty darn appropriate and helpful, and some have come from technical divers.

That raised my eyebrow at well, but on re-reading it, I figured Lynne meant all of the divers on the OP's team (and perhaps even the instructor as well)?
 

Garth

Contributor
Messages
1,062
Reaction score
144
Location
North Carolina USA
# of dives
500 - 999
Listen to TSandM. Her training is without a doubt probably the best training you can get. I found an instructor that mentored me with an equal level of attention to details often missed. I have a deep amount of respect for GUE and DIR as a training agency but if you are diving the setup without the mentality then you are not taking the best part away from their philosophy. I would recommend looking into one of these agencies as a transition to tech if in fact you plan to continue diving with the expectation of having better results.
 
https://www.shearwater.com/products/teric/

Top Bottom