Quiz - Skills & Environment - Diving at Altitude

[EFX]

So what happens to the thinking student taking this test? Here is what likely goes through the mind of an intelligent test taker.

Choice A does not look familiar. Let me think. Did I read that somewhere? Is it true? Why would it be true? [Make it an open book test, and the student will look for the answer. It will not be found. Nothing related to this appears in the required reading (Encyclopedia of Recreational Diving]. It is likely false, but I will hold fire on it.

Choice B looks like it's right, but I have been bitten in the past by "all of the above." Yep, that's choice D, so both A and B might be right. I had better check C.

Well, yeah, choice C is true, that's what you have to do, ...but wait! That's not what the question is asking. It is not asking what you need to do; it is asking why you need to do it. The answer is supposed to finish the "because" statement, and this one does not do that. Even though the information is correct, it cannot be the correct answer.

Well, since choice C cannot be correct, then choice D cannot be correct, either.

Since I have never read anything related to Choice A and I'm pretty sure choice B is correct, that is what I am going to go with.

I'd like to think I'm a little intelligent. I didn't parse the question the way you describe it above and I doubt most of the people responding to it in this thread did either looking at the number of d responses. After reading the question I immediately read all of the choices and quickly determined that b and c were correct. Therefore, d must be correct. I never gave any thought to choice a until after others commented that choice a didn't look correct. So, the general strategy I employ is if there is a "all of the above" choice, then if two answers are correct then the "all of the above" must be the answer. It's unnecessary and a waste of time to look at the fourth choice. Or, if one of the choices is wrong then I can eliminate the "all of the above" choice as being right.

During my career working as an engineer I was called upon to solve problems. Sometimes problems could have many causes so it became a process of eliminating certain causes and narrowing it down to the most likely cause and following through. That's pretty much the process I use with multiple "guess" questions. When the choice comes down to two likely answers then its gets hard and sometimes it does come down to guessing the most likely answer.

 

[scubadada]

I'd like to think I'm a little intelligent. I didn't parse the question the way you describe it above and I doubt most of the intelligent people responding to it in this thread did either looking at the number of d responses. After reading the question I immediately read all of the choices and quickly determined that b and c were correct. Therefore, d must be correct. I never gave any thought to choice a until after others commented that choice a didn't look correct. So, the general strategy I employ is if there is a "all of the above" choice, then if two answers are correct then the "all of the above" must be the answer. It's unnecessary and a waste of time to look at the fourth choice. Or, if one of the choices is wrong then I can eliminate the "all of the above" choice as being right.

During my career working as an engineer I was called upon to solve problems. Sometimes problems could have many causes so it became a process of eliminating certain causes and narrowing it down to the most likely cause and following through. That's pretty much the process I use with multiple "guess" questions. When the choice comes down to two likely answers then its gets hard and sometimes it does come down to guessing the most likely answer.

Testing strategy, you'd be surprised at how good you can get at it. I've taken a lot of very important tests.

 

[BlueTrin]

I'd like to think I'm a little intelligent. I didn't parse the question the way you describe it above and I doubt most of the people responding to it in this thread did either looking at the number of d responses. After reading the question I immediately read all of the choices and quickly determined that b and c were correct. Therefore, d must be correct. I never gave any thought to choice a until after others commented that choice a didn't look correct. So, the general strategy I employ is if there is a "all of the above" choice, then if two answers are correct then the "all of the above" must be the answer. It's unnecessary and a waste of time to look at the fourth choice. Or, if one of the choices is wrong then I can eliminate the "all of the above" choice as being right.

During my career working as an engineer I was called upon to solve problems. Sometimes problems could have many causes so it became a process of eliminating certain causes and narrowing it down to the most likely cause and following through. That's pretty much the process I use with multiple "guess" questions. When the choice comes down to two likely answers then its gets hard and sometimes it does come down to guessing the most likely answer.

I have taken (too) many tests in my life and I do the same than you: for multiple choices, I just go with what looks like the most likely answer.

Seeing two answers that are correct would make me answer ‘all are correct’ without thinking too much about the last one.

 

[boulderjohn]

...except that there are not two correct answers in this example.

 

[tursiops]

...except that there are not two correct answers in this example.

Let me say that differently: there are indeed two correct statements among the possible answers, but only one correct answer to the question posed.

 

[shurite7]

After answering the question, then scrolling down to see what the "correct" response should be, I was surprised what it was. It doesn't make sense. When I moved to MT I did as much research as I could, and still do, on diving at elevations above 1000 feet. Here are some things I've learned, from a physiological point of view:
1. Acclimation (elevation and temperature) - The Bolivian and India military have published some relative information regarding this.
2. Slow the ascent rate, especially in shallower water - Bruce Weinke has good information on this.
3. MOD - This is important for nitrox and trimix dives.
4. Safety and deco stops. The higher the elevation the more critical this becomes.
5. Understanding what theoretical depth actually means in relation to NDL.
6. There are no references of narcosis occurring in shallower depths when diving at elevations above 1000 feet.


I too had issues with my first Shearwater computer (Petral) when diving at altitude. It had to be on before starting the descent. This of course leads to the other issue - equipment, which I am not going to get into.

One last note, I don't like the use of the term high altitude for scuba diving. Sky divers dive from altitude in the atmosphere. Scuba divers dive at elevation, usually fresh water, in mountain lakes on the ground.

 

[BlueTrin]

...except that there are not two correct answers in this example.

For me b) and c) were correct. I didn’t worry about the semantics of ‘because’ because this is a scuba exam ...

Because two statements were correct I just assumed it must be d.

 

[tursiops]

For me b) and c) were correct. I didn’t worry about the semantics of ‘because’ because this is a scuba exam ...

LOL. Now you know. Answer the question, not what you thought it was or what you wished it were, or worse yet, don't care what the question was.

I took a math exam once, two pages of differential equations to solve. At the top, it said, "Read ALL the questions first. Do not answer ANY questions until you have read them all. Right, I thought. Skimmed through most of them and started in. Page 1 went OK. Page 2 got much harder. I slogged along. People started handing in their papers and leaving. I was slogging...nearing the end. The last question said, "Answer only the first page of questions. Next time, follow the instructions."

 

[BRT]

I think I know the answer to this. I worked on it last night after I posted the above response. Boulderjohn is correct in his post, that a difference in altitude would not make any difference in getting narced due to a higher altitude.

Mathematically, working out the ppN2 of air at 6,000 ft is 0.8 atm x 0.79 = 0.63 atm. At 34 ft of fresh water the gauge pressure is another atmosphere so the absolute pressure is: 0.79 + 0.63 = 1.42 atm. taking the difference in pressure gives: 1.42 - 0.63 = 0.79.

At sea level the ppN2 of air is 0.79. At 34 ft depth the gauge pressure is still 0.79 giving 1.58 atm abs. The difference in pressure is 1.58 - 0.79 or 0.79 atm. So, there is no difference in pressure.

Choice "a" is true regardless of altitude. Divers can get narcosis at shallower depths due to their changing physiology day to day and/or diving conditions. I guess I read too much into that choice because the question was about altitude.

"Special procedures must be followed when diving at altitude because nitrogen narcosis may occur at shallower depths" is true?

 

[tursiops]

"Special procedures must be followed when diving at altitude because nitrogen narcosis may occur at shallower depths" is true?

No.