Wreck Diver Certification (Blindfolded reel-in)

[tursiops]

Yeah ok. Just like the guy who tells the cop he doesn't have to show ID because he did nothing wrong and the traffic stop was unlawful. The cop will acknowledge his error and happily wave the motorist on his way, possibly thanking him for pointing out his transgression so he won't do it again.

@tursiops Suggesting a student disobey his instructor and refuse to do a skills test will most likely not result in a desirable outcome. If you'd like a more complete explanation of how people tend to think and act and why a student taking your advice and refusing to follow the direction of the instructor would likely fail the course then we can discuss it in private but but not here.

You are wrong.

 

[gamon]

You are wrong.

I offered to explain to you in private messaging why your reasoning is incorrect as it pertains to human behavior and what "should" happen versus what "will probably happen" if a student refuses to follow the directions of an instructor during a training course.

You can proclaim that anyone who disagrees with you is wrong but that changes nothing and worse yet it deprives you of much needed learning opportunity.

 

[tursiops]

I offered to explain to you in private messaging why your reasoning is incorrect as it pertains to human behavior and what "should" happen versus what "will probably happen" if a student refuses to follow the directions of an instructor during a training course.

You can proclaim that anyone who disagrees with you is wrong but that changes nothing and worse yet it deprives you of much needed learning opportunity.

A blindfolded reel-in on Dive 2 of the PADI wreck course breaks two standards. The instructor was wrong too.

 

[gamon]

A blindfolded reel-in on Dive 2 of the PADI wreck course breaks two standards. The instructor was wrong too.

Perhaps but irrelevant. If the student made the mistake of pointing that out to the instructor and refused to participate in the drill, he wouldn't be getting his card. At least not from that instructor.

 

[tursiops]

Perhaps but irrelevant. If the student made the mistake of pointing that out to the instructor and refused to participate in the drill, he wouldn't be getting his card. At least not from that instructor.

If that were to happen, the instructor could lose his credentials. Even instructors have to play by the rules.

 

[gamon]

If that were to happen, the instructor could lose his credentials. Even instructors have to play by the rules.

Unless the instructor provided a reason such as the student failed to demonstrate adequacy in the requisite skills. Or whatever other reason to support his unwillingness to sign off on a student who refused to follow instructions.

 

[lizardland]

I have no experience in any of this, but I am curious as to how a diver who is blindfolded is going to be expected to maintain good buoyancy control without relying upon tactile information - like touching the bottom, sides or top?

Do you just put a lot of tension on the line and try to keep it in front of you while you reel? I would think that if you are in a total silt out, you could sorta crawl on the bottom, its not like you are going to mess up the vis?

Number one rule is get out alive. The easiest way of avoiding problems when reeling back in during a silt out or other loss of vis is to not reel back in the first place. Tie it off somewhere convenient or even just lock it off and drop it. Worst outcome is that you lose a reel plus if there are other people caught in the same silt out then your line may be a life saver.

How you maintain buoyancy control when following a line isn't a straightforward answer. First, if you've been silted out then who cares about buoyancy control? You are not going to make the situation worse by bouncing off the bottom. Buoyancy becomes a question of being floaty enough to be able to move efficiently and not floaty enough that you are either going to pull the line into somewhere bad or get pulled off the line completely. If anything, you probably want to maintain slightly negative buoyancy but not so much that a good inhale won't give a bit of lift if you need it.

Being totally blind is very unusual, especially on a wreck. To be unable to see anything at all is going to be maybe a triple light failure (and if you're with a buddy then that needs 6 lights to fail). In a cave disturbing clay will turn the water to paint, on a wreck then maybe if you disturb a bulk cargo or something collapses it might have the same effect? Generally you are going to see something even if it is only inches ahead. Any visual cue is useful.

Same goes for tactile cues as well. If you're the guy in front then you have one hand on the line and a free hand that you can use. Or just dragging a fin tip will give you some info on where you are in relation to the bottom. If you're the guy at the back then you have no free hands (you will be maintaining touch contact with your buddy and the line) so you have to take whatever contact with your environment you can get. Stuff will touch you as you go. You can also feel on the line if you are drifting up. Worst case, there's a ceiling above you so you can only go so far.

The other thing is you saw where you were going on the way in. You will have an idea of where the line went, where you went up, where you went down, where it's flat, etc, so you can anticipate what's coming to some extent on the way out. The absolute key skill of line laying is not about picking the best route in, it is considering where to put the line for the best route out. Personally I'd be looking to avoid having the line mid-water, I'd rather go around something than over it, I'd be looking for line placements that avoid anything that would be a pain to negotiate if blind, etc just so that I'm avoiding potential issues for a blacked-out exit.

 

[Wibble]

A rebreather brings its own issues. If you're in a situation where you can't see the way out then what do you do when you can't see your ppo2? SCR your way out? Just pray that whatever O2 addition system you're using will keep up while you're blind? (A level of faith most of us aren't willing to accept in normal circumstances)

Not so much an issue in wrecks but clay in a cave will turn the water to soup. I've been in many a sump where a misplaced fin will make you think someone has just poured brown paint over your mask.

All things being equal, you’d have the computer controller maintaining your setpoint (if ECCR) or you’d be used to periodic manual injection with the aid of the CMF if a manual (MCCR). Flashy light HUD can be made out in a silt-out.

Silt-outs on wrecks tend to be less dense than clay sediment in caves — where you can barely see your torch light pressed to your faceplate. Obviously good core skills are essential to both not kick up silt in the first place and to gently back out of trouble without making things worse.

But the point remains: when diving a rebreather you effectively have unlimited gas thus the lizard brain has one less thing to panic about.

On open circuit once you are entangled in fishing line on a wreck, silted out or lost inside, the lizard brain kicks off and generally makes things far worse or at least way more unpleasant

 

[lizardland]

All things being equal, you’d have the computer controller maintaining your stepping (if ECCR) or you’d be used to periodic manual injection with the aid of the CMF if a manual (MCCR). Flashy light HUD can be made out in a silt-out.

Silt-outs on wrecks tend to be less dense than clay sediment in caves — where you can barely see your torch light pressed to your faceplate. Obviously good core skills are essential to both not kick up silt in the first place and to gently back out of trouble without making things worse.

But the point remains: when diving a rebreather you effectively have unlimited gas thus the lizard brain has one less thing to panic about.

On open circuit once you are entangled in fishing line on a wreck, silted out or lost inside, the lizard brain kicks off and generally makes things far worse or at least way more unpleasant

I don't disagree having hours of gas does massively alleviate stress.

I've been in more than a few situations where visibility was so bad that I couldn't see my HUD. You don't always have the luxury of just not kicking the silt up in the first place. I've had crap washed down sumps while I've been in them, I've been in caves where sudden storms have turned the sump to soup in minutes, I've had to transit passages that looked like a herd of cattle had passed through before me, squeezing through holes in muddy caves then it's inevitable you are going to destroy the vis. We don't always have control of our environments and if "just don't do it in the first place" was easy then we'd have no need of emergency procedures because 99% of emergencies are avoidable.

Anyhow, the point also remains that "always know your ppo2" is generally accepted as the absolute foundation of CCR diving. We assume that any given unit at any given time may decide to shite the bed, so much so that in benign conditions we'd be checking ppo2 every few minutes at the most. It seems weird that in stressful conditions we're happy to give that up, assume the unit will work perfectly for a prolonged time and ignore the most basic principle of CCR diving when we aren't willing to accept that when conditions are good and stress-free. Realistically, eCCR is generally reliable enough that you will get away with it. It will just keep working. But that doesn't alter the fact that it means sacrificing one of the basic keep-you-alive principles in an already difficult situation.

 

[J-Vo]

I have no experience in any of this, but I am curious as to how a diver who is blindfolded is going to be expected to maintain good buoyancy control without relying upon tactile information - like touching the bottom, sides or top?

The line is your reference. Make an "OK" around it and if it touches your fingers you know witch way you are drifting. This is one of the reasons you don't try to reel it in during a black out.