Intro to recreational deep diving

[String]

For my AOW we did a timed exercise. All but one of us did it FASTER at depth. I know I was Narc'd - no doubt. We figured that the guy that was timing us was also narc'd and he timed us wrong.....

Probably not that. You can try this on land. Give a human a puzzle or task he's never seen before and time him doing it. Then a few minutes later give him the same task or same type of problem - you'll find he is MUCH MUCH quicker that second time. The first few repeats the human brain rapidly adapts at performing tasks.

The problem is going under water although narcosis in theory can slow down this that slow down is insignificant when compared to the natural speed up due to the brain adapting to the puzzle.

That's why i like surprise tests of something they do often but aren't expecting like maybe a mask clear, compass nav with reciprocal or similar - to an extent it removes that puzzle-adaptation problem.
Although at 30m maximum depth especially in clear warm conditions someone may not be narked enough to have any real effect anyway. The fact that PADI at least you can do "deep" at 19m or more where im certain you wouldnt notice any difference at all thus defeating the purpose of it.

 

[Rick Murchison]

My narcosis demo has three parts:
1. Dexterity - Topside, I have them write, on half a slate, an easy-to-remember phrase... like this one: "There are only two things that money won't buy - true love and home grown tomatoes." and record how long it took to write it.
At depth I have them do it again on the other half of the slate and record how long it took. They have what they've already written as a reference should they have trouble remembering. After the dive we compare time, penmanship and any perceptive differences or difficulties they noticed while performing the task. Results vary from "no difference" to indecipherable henscratches that "looked perfectly good to me when I wrote it!"
2. Mental math - I use multiplication by 11... using the "ten times the number plus the number" method. Answers are given using one hand. I have them practice with half a dozen problems or so before the dive to eliminate the "second time's easier" effect.
They're allowed to use their slate under water if they need to.
I keep track of how long it takes them to solve the problems, whether they give the right answers, and whether they need to use the slate. After the dive, if they missed any, I have 'em do it again so they can see that they're able to do it topside. We discuss any differences they perceived between the topside and underwater exercise. Again, results are variable... and often interesting.
2. Memory item. They're told that after the writing and mental math, I'll wave goodbye to them so they can continue the dive, but that they are to record their dive time, depth and tank pressure on their slate before leaving. About half forget
Using those three, almost everyone is able to identify narcosis in themselves, and to modify their future dive planning to include accomodation for the associated shortcomings in ability.
Rick

 

[BDSC]

My narcosis demo has three parts:
1. Dexterity - Topside, I have them write, on half a slate, an easy-to-remember phrase... like this one: "There are only two things that money won't buy - true love and home grown tomatoes." and record how long it took to write it.
At depth I have them do it again on the other half of the slate and record how long it took. They have what they've already written as a reference should they have trouble remembering. After the dive we compare time, penmanship and any perceptive differences or difficulties they noticed while performing the task. Results vary from "no difference" to indecipherable henscratches that "looked perfectly good to me when I wrote it!"
2. Mental math - I use multiplication by 11... using the "ten times the number plus the number" method. Answers are given using one hand. I have them practice with half a dozen problems or so before the dive to eliminate the "second time's easier" effect.
They're allowed to use their slate under water if they need to.
I keep track of how long it takes them to solve the problems, whether they give the right answers, and whether they need to use the slate. After the dive, if they missed any, I have 'em do it again so they can see that they're able to do it topside. We discuss any differences they perceived between the topside and underwater exercise. Again, results are variable... and often interesting.
2. Memory item. They're told that after the writing and mental math, I'll wave goodbye to them so they can continue the dive, but that they are to record their dive time, depth and tank pressure on their slate before leaving. About half forget
Using those three, almost everyone is able to identify narcosis in themselves, and to modify their future dive planning to include accomodation for the associated shortcomings in ability.
Rick

Hey Rick,

Just curious. What kinds of depths are you talking about here?

BDSC

 

[Rick Murchison]

Hey Rick,

Just curious. What kinds of depths are you talking about here?

BDSC

100-130' (30-40M) The site I use most is 107' (32M)
Rick

 

[BDSC]

Thanks!

 

[jjhill]

So in reality then as your certification says - you are only qualified and safe to dive in conditions similar to you were trained in. You aren't safe in cold water.



I fail people who cant meet the required standards for the course im teaching. Given mask removal is a core, essential and very simple basic skill nobody is ever going to pass if they can't do that.



How many times do you want it to happen? Only takes once on a wall or no solid bottom or a dive where you require stops for someone to get hurt. Masks can get kicked, masks can get dislodged, they can get banged, caught on help, moved in currents. Hoods can trap air and ball back away from the mask, masks can mist up and need removing to clear. Countless reasons as to why you cant guarantee a mask can stay on your face 100% of the time.



That's nice - so you maybe safe to dive in warm water. What happens if you lose it in cold water? Just think "Its ok, i can replace this in warm water" ?



It would appear your training is or was very substandard if you are unable to master a basic skill that students never exposed to to open water before manage on the first attempt.



That's nice - how much do you want to gamble blindly hoping it never happens in real life? Just because your mask hasnt been dislodged in the small number of dives you have doesnt mean it wont ever happen. Also it doesn't have to be kicked off - simply being banged or moving in a current can move it away from the hood seal leaving you with identical problems to having it removed. And then it would appear you are in serious trouble due to being unable to perform the quick and simply skill required to fix it.



Again its clear you really have no idea as to the many reasons why a mask can become dislodged in ANY condition.



Find me an agency that doesn't REQUIRE at least one full mask removal and at least another full flood in open water. I cant think of one. Its required for PADI,SSI,NAUI,BSAC,CMAS affiliates and all the major ones i can think of. Its there for a reason. You had to do it in warm water so why do you think the skill suddenly doesnt matter in cold water?



You start without gloves in confined, then with gloves and hood in confined then graduate to open water. An instructor would be negligent in not allowing his student to attempt the skill in the protective clothing required for open water diving.



Its down to the instructor. If someone takes 5-6 minutes to clear a mask in my view they dont fit the "Confident and competent" definition BSAC require. An instructors ultimate goal is to ensure the student is safe to dive without an instructor. Someone who takes several minutes or is completely incapable of a basic vital skill like a mask replacement i dont think would meet any sane instructors definition of safe.



Thereby probably breaking standards too. Lovely.
Expecting a qualified diver to be able to remove and replace his mask is not holding a higher standard at all - its expecting an absolutely basic minimal skill level required to dive safely.

Good post. I am quite happy that I decided to get certified where I live in Alberta rather then on a warm water holiday. The local diving here is cold water diving with average temperature in the mid to high 40's.

For our class our first pool session was just to get used to the gear but by the second pool session gloves and hoods were already required for those who were doing local water checkouts and strongly recommended for those doing warm water referal checkouts. We drilled all the skills in the pool with gloves and hoods, which when it came to open water checkout made the transition that much easier.

I for one am really glad the agency (Naui) and the instructors made us do it. Just the initial cold water shock when pulling your mask off in cold water made the skill that much harder, I couldn't imagne how hard it might be if you were also doing it with gloves on for the first time.

I do a lot of local diving and it is not uncommon for people who are used to only diving on warm water vacations struggle with their first few cold water dives.

To the poster with the trouble with hairs caught in the mask, keep practising. It is a worthwhile skill to know. Once you have it down with a 5 fingered glove try it with a 3 fingered mitt. For me I find it helps to get a thumb under your hood at the checkbone and thn run it under the hood across the forhead. This will not only get hairs out of the way but will also get your mask tucked under your hood creating a better seal.

Also not to be relied upon, but do not forget the value of a buddy who can spot the misplaced hairs easier and help you out.

 

[TSandM]

My narcosis demo has three parts:
1. Dexterity - Topside, I have them write, on half a slate, an easy-to-remember phrase... like this one: "There are only two things that money won't buy - true love and home grown tomatoes." and record how long it took to write it.
At depth I have them do it again on the other half of the slate and record how long it took. They have what they've already written as a reference should they have trouble remembering. After the dive we compare time, penmanship and any perceptive differences or difficulties they noticed while performing the task. Results vary from "no difference" to indecipherable henscratches that "looked perfectly good to me when I wrote it!"
2. Mental math - I use multiplication by 11... using the "ten times the number plus the number" method. Answers are given using one hand. I have them practice with half a dozen problems or so before the dive to eliminate the "second time's easier" effect.
They're allowed to use their slate under water if they need to.
I keep track of how long it takes them to solve the problems, whether they give the right answers, and whether they need to use the slate. After the dive, if they missed any, I have 'em do it again so they can see that they're able to do it topside. We discuss any differences they perceived between the topside and underwater exercise. Again, results are variable... and often interesting.
2. Memory item. They're told that after the writing and mental math, I'll wave goodbye to them so they can continue the dive, but that they are to record their dive time, depth and tank pressure on their slate before leaving. About half forget
Using those three, almost everyone is able to identify narcosis in themselves, and to modify their future dive planning to include accomodation for the associated shortcomings in ability.

Rick, I wish I'd had you for my deep dive specialty.

 

[Dtaine]

My narcosis demo has three parts:
1. Dexterity - Topside, I have them write, on half a slate, an easy-to-remember phrase... like this one: "There are only two things that money won't buy - true love and home grown tomatoes." and record how long it took to write it.
At depth I have them do it again on the other half of the slate and record how long it took. They have what they've already written as a reference should they have trouble remembering. After the dive we compare time, penmanship and any perceptive differences or difficulties they noticed while performing the task. Results vary from "no difference" to indecipherable henscratches that "looked perfectly good to me when I wrote it!"
2. Mental math - I use multiplication by 11... using the "ten times the number plus the number" method. Answers are given using one hand. I have them practice with half a dozen problems or so before the dive to eliminate the "second time's easier" effect.
They're allowed to use their slate under water if they need to.
I keep track of how long it takes them to solve the problems, whether they give the right answers, and whether they need to use the slate. After the dive, if they missed any, I have 'em do it again so they can see that they're able to do it topside. We discuss any differences they perceived between the topside and underwater exercise. Again, results are variable... and often interesting.
2. Memory item. They're told that after the writing and mental math, I'll wave goodbye to them so they can continue the dive, but that they are to record their dive time, depth and tank pressure on their slate before leaving. About half forget
Using those three, almost everyone is able to identify narcosis in themselves, and to modify their future dive planning to include accomodation for the associated shortcomings in ability.
Rick

I did some timed tests, comparing at the surface and at depth, for the first two dives of my deep diver specialty course. I was faster at depth than some of the people were on the surface. I thought the best test I was given though was on the third dive, because it included a dexterity and math exercise similar to what you've described. Basically the instructor handed me a slate at depth that asked me to write my full name backwards (dexterity) and answer a few math problems.

The last thing on the slate was the most hilarious though, it said "Draw a Kangaroo." I can only imagine how hilarious it was to watch me try that one.

Good post. I am quite happy that I decided to get certified where I live in Alberta rather then on a warm water holiday. The local diving here is cold water diving with average temperature in the mid to high 40's.

For our class our first pool session was just to get used to the gear but by the second pool session gloves and hoods were already required for those who were doing local water checkouts and strongly recommended for those doing warm water referal checkouts. We drilled all the skills in the pool with gloves and hoods, which when it came to open water checkout made the transition that much easier.

I for one am really glad the agency (Naui) and the instructors made us do it. Just the initial cold water shock when pulling your mask off in cold water made the skill that much harder, I couldn't imagne how hard it might be if you were also doing it with gloves on for the first time.

I do a lot of local diving and it is not uncommon for people who are used to only diving on warm water vacations struggle with their first few cold water dives.

To the poster with the trouble with hairs caught in the mask, keep practising. It is a worthwhile skill to know. Once you have it down with a 5 fingered glove try it with a 3 fingered mitt. For me I find it helps to get a thumb under your hood at the checkbone and thn run it under the hood across the forhead. This will not only get hairs out of the way but will also get your mask tucked under your hood creating a better seal.

Also not to be relied upon, but do not forget the value of a buddy who can spot the misplaced hairs easier and help you out.

I too am glad I got my OW and AOW in cold water w/ a full 7 mm suit, gloves, hood, etc. It forced me to be more proficient in some of the basic skills like mask removal.

For the OP, I'd strongly recommend getting proficient at mask replacement before hitting 120', perhaps getting a different brand of gloves or going with a slightly thinner pair would help.

 

[Atomic_Diver]

i am sorry i did not know it would be precived as something to go after... your right about trimix its definatly not something to play with, i was just saying that i heard about the recerational trimix course and thought i would say something in case he was wanting to look into something.