kwinter
Contributor
I remember back in the early days our ascent rate was to follow our bubbles up without passing them. I have no idea how fast bubbles rise, but I'm sure it is a lot faster than what is considered safe today.
Who should I listen to?
- Thread starter ARDory
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I remember back in the early days our ascent rate was to follow our bubbles up without passing them. I have no idea how fast bubbles rise, but I'm sure it is a lot faster than what is considered safe today.
I would say, as a general principle, memorize/learn exactly whatever the PADI book and your instructor tell you, regardless of what other sources may say. Now, if there is an inconsistency between the book and the DVD, you should of course point it out to the instructor. The replies here have been more than thorough, but the bottom line is that you're taking a PADI course, so for the time being you should memorize (that is, learn) the information exactly as it is taught by PADI.
Once you pass the course, then by all means start questioning what you learned in the course. As you will soon discover from reading SB, PADI is not the ultimate authority on diving, and expert opinions differ on just about every aspect of diving. Approach your PADI Open Water dive course like any other course you might have taken: Follow just what you are taught, as that will become the foundation for you to learn more on your own later. Then, as you learn more from other sources, you will begin to be able to form your own opinions and perhaps choose to modify aspects of the foundation that you learned. Trying to assimilate information from different sources WHILE taking the PADI course is not something I would recommend, as it will just confuse you.
I can't tell you how many people must come to SB not long after being certified and think/post with some degree of frustration, "But in MY Open Water course I was taught to do it a different way!" Yes, there are all kinds of opinions and schools of thought on almost every issue in diving, just as there are in other disciplines. PADI's intent is to teach you one way of doing things. Learn it. Practice it. And then later, when you've got the foundation down pat, feel free to try broadening your horizons.
Again, my reply is intended to be broader than your specific question. I think the specific question regarding 30 fpm versus 60 fpm versus some other ascent rate has been thoroughly answered.
Once you pass the course, then by all means start questioning what you learned in the course. As you will soon discover from reading SB, PADI is not the ultimate authority on diving, and expert opinions differ on just about every aspect of diving. Approach your PADI Open Water dive course like any other course you might have taken: Follow just what you are taught, as that will become the foundation for you to learn more on your own later. Then, as you learn more from other sources, you will begin to be able to form your own opinions and perhaps choose to modify aspects of the foundation that you learned. Trying to assimilate information from different sources WHILE taking the PADI course is not something I would recommend, as it will just confuse you.
I can't tell you how many people must come to SB not long after being certified and think/post with some degree of frustration, "But in MY Open Water course I was taught to do it a different way!" Yes, there are all kinds of opinions and schools of thought on almost every issue in diving, just as there are in other disciplines. PADI's intent is to teach you one way of doing things. Learn it. Practice it. And then later, when you've got the foundation down pat, feel free to try broadening your horizons.
Again, my reply is intended to be broader than your specific question. I think the specific question regarding 30 fpm versus 60 fpm versus some other ascent rate has been thoroughly answered.
Yes. Correct. The rule was, "Don't ascend faster than your smallest bubbles." That assumed the small bubbles traveled slower than 60 ft/min. Larger bubbles would increase size as well as speed. You may remember that product that appeared in dive magazine ads - 3 small balls in a carrier that could clamp to a hose? That was a commercial take on that ascent strategy. The bubbles were supposed to travel no faster than 60 ft/min. You were supposed to release one and follow it up. I never saw any in a dive shop.
DevonDiver
N/A
Following bubbles: I'm sketchy on the theory with this... as the bubble ascends, it expands. Does that expansion (increase in volume/buoyancy) cause it to accelerate? Progressively accelerate on ascent? Or do other factors (friction/water resistance) quickly regulate a maximum velocity regardless of size?
I've always assumed you would follow the smallest bubble, from each exhalation... abandoning the current bubble each time you produced more?
Personally, I never understood the difficulty with speed - distance - time calculations. All you need is a depth gauge, watch, brain and eyes...
Scuba Diving Skills and Techniques - How to Judge Your Ascent Rate
I've always assumed you would follow the smallest bubble, from each exhalation... abandoning the current bubble each time you produced more?
Personally, I never understood the difficulty with speed - distance - time calculations. All you need is a depth gauge, watch, brain and eyes...
Scuba Diving Skills and Techniques - How to Judge Your Ascent Rate
The smallest bubbles rule was just a rule of thumb. The idea was that each time you exhaled you just never wanted to be going faster than the tiny ones escaping your exhaust tee. As bubbles get bigger they'd expand and be going faster than what was considered safe. The concept was no way an accurate measurement of one's rate of ascent.
victorzamora
Contributor
One thing you're missing, Andy, is that bubbles will split. A bubble will rise, accelerate, and will frequently shed smaller bubbles. Those smaller bubbles are the ones to follow. My thing is this: If I'm on a shallow, easy rec dive and don't care to keep track of depth/time (or my depth gauge fails) I can just make sure I'm going slower than ALL of my bubbles. The smallest are the slowest, and making sure I don't pass any on the way up is easy. Now that I've started really focusing on my dive quality (or trying 
) I've started getting a feel for ascent rates. I can normally ride my computer (without looking) at 30fpm. The alarm goes off at 31fpm. I believe the last "bar" initiates at around 25fpm. I can often keep it in that range by feel.....but the bubbles are a great visual for new divers that are getting a feel for it.
) I've started getting a feel for ascent rates. I can normally ride my computer (without looking) at 30fpm. The alarm goes off at 31fpm. I believe the last "bar" initiates at around 25fpm. I can often keep it in that range by feel.....but the bubbles are a great visual for new divers that are getting a feel for it.
In real diving (not test taking) don't freak out about the numbers quite so much. There is no tape measure to use underwater, and there is no car-like speedometer to tell you what you are ascending at number wise. If you have a computer, it'll give you some kind of bars as a gauge based on its algorithm (which you need to understand thoroughly). Use it, use the smallest bubbles (and at least for me), use what your ears are telling you - use them all to help gauge yourself.
You'll find in the water, it can be hard to rise at any constant rate as a beginner, because you have to manage the expanding air in your BCD, kick, breath, think, watch your buddy etal.
But don't freak out about it. You don't have to be exact or super smooth to be safe (it is however what you strive to be able to do as you gain more experience). If you find yourself moving up too fast ie your computer is bleating at you or your ears are popping, stop yourself and wait a few secs at that depth until your computer clears and you re-gain control, and then proceed under control. 30'/min is actually agonizingly slow. Try walking at a constant pace at 30'/min and you'll get the idea. Its way slower and requires more patience than you think.
The best by far way is to ascend up a line of some sort. Then you can hold on to the line to gauge your ascent speed and stay in control. If its there, use it - everyone does and its the safest thing to do. Always do the safest thing and don't succumb to peer pressure or your ego to do otherwise. It should go without saying, but if you read the Accident section, well.....
You'll find in the water, it can be hard to rise at any constant rate as a beginner, because you have to manage the expanding air in your BCD, kick, breath, think, watch your buddy etal.
But don't freak out about it. You don't have to be exact or super smooth to be safe (it is however what you strive to be able to do as you gain more experience). If you find yourself moving up too fast ie your computer is bleating at you or your ears are popping, stop yourself and wait a few secs at that depth until your computer clears and you re-gain control, and then proceed under control. 30'/min is actually agonizingly slow. Try walking at a constant pace at 30'/min and you'll get the idea. Its way slower and requires more patience than you think.
The best by far way is to ascend up a line of some sort. Then you can hold on to the line to gauge your ascent speed and stay in control. If its there, use it - everyone does and its the safest thing to do. Always do the safest thing and don't succumb to peer pressure or your ego to do otherwise. It should go without saying, but if you read the Accident section, well.....
DevonDiver
N/A
[Off-Topic... apologies]
The technique I use is to deploy a DSMB:
Two fingers over two fingers = 3m/min
Hand over hand (touching) = 9m/min
Hand over hand (1ft spread) = 18m/min
I've had students do this in black/no-mask... it works. (stops conducted = knot pre-positioned a 3m intervals on the line; 3m, 6m, 9m, etc...)
No-viz, unsupported ascents... great fun
[back on-topic, carry on as you were... and Happy New Year from the Philippines]
Interesting idea. I like it!
I have not been doing black mask ascent drills with many students. I think I am going to try and integrate this into some classes this year. Thanks.
iluvtheocean
Contributor
i should say always listen to the man -- we're always right -- even when we're wrong!
but yes for class & testing purposes -- answer the question per the book! and read the question carefully....
otherwise 30 is good just like everyone is saying... bottom line.. in class follow the book & the instructor -- after you're certified - it's up to you, it's your life in your hands..
but yes for class & testing purposes -- answer the question per the book! and read the question carefully....
otherwise 30 is good just like everyone is saying... bottom line.. in class follow the book & the instructor -- after you're certified - it's up to you, it's your life in your hands..
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