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As I said, bingo gas.
Split from Exploration dives without a computer
- Thread starter TheRedHead
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Diver Dennis
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That's what I thought Lynne. A lot of divers don't understand it is just a core set up that has to be done the same way.
JeffG
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LOLPerroneFord:
JeffG
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and where do you think the misinformation is coming from?PerroneFord:
Charlie99
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OK, then. An alternative way of describing dive planning which is essentially the same is:Thalassamania:
1. Rock bottom (or as you call it, "bingo") is 100psi per 10' + 200, never less than 750.
2. US Navy no deco limits, using standard square profile table calculations. These can be roughly approximated as NDL + Depth' = 120 minutes.
3. Each dive ends with 1/2 depth stop of 3 minutes, plus 3 minutes at 15'. (Naked USN table is rather agressive, but with these stops becomes pretty conservative).
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You didn't call out these rules, but a couple of useful approximation on equivalent air depth are:
4. Use 80% of actual depth on EAN32 and 75% of actual depth on EAN36 as the equivalent air depth.
PerroneFord
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Yes Snowbear, you are correct. Standard gases are great. And certainly DIR. However, not everyone can dive Helium.
Charlie99
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.. deleted. Accidently duplicated this post by "quoting" instead of "editing". Scroll down a couple.
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Charlie99:
can I frame this? laminate it, whatever?
yes, perrone. its his form of tough love. Jeff knows A LOT so he should "share" more...which for some of us involves going out on a limb occasionally.
A certain wise diver named Charlie 99 as "most knowledgable" in a pm. so, he is on my radar and I am all ears.
Charlie99
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NDL
"Every dive is a deco dive" is an oft repeated phrase. The risk from an immediate ascent only slowly increases as one approaches and then exceeds traditional NDL. A few extra minutes spent in the ascent and stops on the way up is much more important than whether your are a couple minutes one way or the other of NDL. I use a computer with a bargraph that shows loading as a fraction of maximum allowable NDL loading. Meanwhile, I do some tracking in my head vs. the PADI limits (I dive often enough that it isn't all that hard to keep in memory this relatively small set of numbers, particularly since my computer has essentially the same numbers for NDL).
My on-the-fly calculations are similar, but include some seat of the pants and gut feeling sort of approximations that allow for multilevel profiles. In one sense, I really just know whether my loading is light, medium, heavy, or loaded to the gills.
I also have a feeling whether this is in the fast compartments or the slower ones. (A square profile deep dive rapidly loads the fast compartments, but OTOH, they will also offload quickly. A square profile dive to 70 or 80' is what in real life leads to a dive with the heaviest loading still left after one of my standard ascents).
I wouldn't go so far as to say that I am actually tracking average depth numerically, but on the other hand, I do keep a crude mental tally of both overall dive average depth and the average depth over the last 10 minutes or so. My deep stops depend only upon average depth in the 10 minutes or so before starting my ascent, so even on a dive with 130' max depth, my first stop will be 40' is my last 10 minutes was 60 or 80'.
I also use the bargraph of an Oceanic hockey puck computer to confirm my gut feeling on loading levels (or vice versa -- it's debatable whether my internal tracking is primary and the computer a backup, or it's the other way around).
I also have tucked away in memory a handful of precomputed multilevel dive profiles ---- once you start factoring in gas consumption and rock bottom on an AL80, you can get pretty close to most acceptable profiles with just one or two profiles per starting depth. I.E. Having precomputed multilevel dives for 130' max, 100' max, and 80' max covers most of my diving. The precomputed profiles are from the PADI Wheel (or my equivalent "Flat Wheel" table), but you'll end up with pretty much the same profiles if you do them in Decoplanner or V-Planner.
ASCENT PROFILE
My ascent profile is neither as biased towards the shallow side as the old PADI 60fpm + 3 min at 15'; nor as biased towards the deep side as the old GUE 1 minute every 10' from 80% of ata/75% of depth all the way to the surface. My ascent profile attempts to emulate with just 1 ascent rate and 3 stops, what comes out of a gradient factor program such as Decoplanner (with low gradient factors) or out of a dual phase/bubble model program such as V-Planner when using high levels of conservatism.
1. Stop depths. For ascents from 80' or less, 1st stop is 40', 2nd stop 25', 3rd stop is a 20' to 8' glide. For 100+' these become 50', 30', and 20' to 10'.
2. Depending upon how heavily loaded I am and how bored I am with what's around the stop depths, the basic ascent is basically 1 min at firsts top, 2 minutes including move time up to the stop for 2nd stop, and 3 minute for 3rd stop. The minimal ascent is a minute at 1/2 depth, 3 min in the 20 to 10' stop. If heavily loaded, my stops become 2 minutes at 40', 3 at 25-30', and 4+ minutes at "safety stop" depths. If my loading is mostly in the faster tissues (coming up directly from deeper dive), then I bias things a bit towards the deeper stops. If heaviest loading is in the medium speed compartments (such as from a 50 minute air dive to 60' flat bottom), the everything get moved a bit shallower to 40' / 25' to 20' / and 15' to 5'.
3. Nominal ascent rate between stops is 30fpm, but I don't sweat it too much. How I really control my overall ascent rate is by looking at my computer, taking the current runtime, rounding it up to the next minute (doesn't show seconds), and adding to it my total ascent time (typically 6 to 9 minutes). That give me the end time of my 20-8' safety stop/glide. The end of my 1st stop is 1 or 2 minutes, plus ascent time to 40' or 50'. End time for my second stop is obviously between those two times, and is closer to the 1st stop ending time than the surfacing time.
All of this may sound very complicated, but you will be surprised at how easily it all comes together if you try it the next few times you start an ascent. After a while, you really just have to remember starting time, what you have chosen for surfacing time, and after than you just glance at your computer or bottom timer and you pretty much can automatically tell if you are at the depth you should be for that runtime.
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ROCK BOTTOM
As I posted about 3 years ago, this extend ascent requires about the same amount of air that is required for an emergency problem solving + ascent with a panicked diver, so there is no need to increase rock bottom numbers to account for the slow ascent and extra stops.
I just use the simple 100psi per 10' of depth, but never less than 700psi. This is true rock bottom, not just a "let's start ascent somewhere around this psi". Rarely do I ever get to rock bottom.
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The title of the thread is "Exploration Dives Without A Computer". My method could be used without a computer, but in reality is more along the line of how to intelligently dive WITH a computer.
I suspect that there are other divers out there that have developed or evolved similar methods of controlling their profiles, but have not seen anyone post their methods.
"Every dive is a deco dive" is an oft repeated phrase. The risk from an immediate ascent only slowly increases as one approaches and then exceeds traditional NDL. A few extra minutes spent in the ascent and stops on the way up is much more important than whether your are a couple minutes one way or the other of NDL. I use a computer with a bargraph that shows loading as a fraction of maximum allowable NDL loading. Meanwhile, I do some tracking in my head vs. the PADI limits (I dive often enough that it isn't all that hard to keep in memory this relatively small set of numbers, particularly since my computer has essentially the same numbers for NDL).
My on-the-fly calculations are similar, but include some seat of the pants and gut feeling sort of approximations that allow for multilevel profiles. In one sense, I really just know whether my loading is light, medium, heavy, or loaded to the gills.
I also have a feeling whether this is in the fast compartments or the slower ones. (A square profile deep dive rapidly loads the fast compartments, but OTOH, they will also offload quickly. A square profile dive to 70 or 80' is what in real life leads to a dive with the heaviest loading still left after one of my standard ascents).
I wouldn't go so far as to say that I am actually tracking average depth numerically, but on the other hand, I do keep a crude mental tally of both overall dive average depth and the average depth over the last 10 minutes or so. My deep stops depend only upon average depth in the 10 minutes or so before starting my ascent, so even on a dive with 130' max depth, my first stop will be 40' is my last 10 minutes was 60 or 80'.
I also use the bargraph of an Oceanic hockey puck computer to confirm my gut feeling on loading levels (or vice versa -- it's debatable whether my internal tracking is primary and the computer a backup, or it's the other way around).
I also have tucked away in memory a handful of precomputed multilevel dive profiles ---- once you start factoring in gas consumption and rock bottom on an AL80, you can get pretty close to most acceptable profiles with just one or two profiles per starting depth. I.E. Having precomputed multilevel dives for 130' max, 100' max, and 80' max covers most of my diving. The precomputed profiles are from the PADI Wheel (or my equivalent "Flat Wheel" table), but you'll end up with pretty much the same profiles if you do them in Decoplanner or V-Planner.
ASCENT PROFILE
My ascent profile is neither as biased towards the shallow side as the old PADI 60fpm + 3 min at 15'; nor as biased towards the deep side as the old GUE 1 minute every 10' from 80% of ata/75% of depth all the way to the surface. My ascent profile attempts to emulate with just 1 ascent rate and 3 stops, what comes out of a gradient factor program such as Decoplanner (with low gradient factors) or out of a dual phase/bubble model program such as V-Planner when using high levels of conservatism.
1. Stop depths. For ascents from 80' or less, 1st stop is 40', 2nd stop 25', 3rd stop is a 20' to 8' glide. For 100+' these become 50', 30', and 20' to 10'.
2. Depending upon how heavily loaded I am and how bored I am with what's around the stop depths, the basic ascent is basically 1 min at firsts top, 2 minutes including move time up to the stop for 2nd stop, and 3 minute for 3rd stop. The minimal ascent is a minute at 1/2 depth, 3 min in the 20 to 10' stop. If heavily loaded, my stops become 2 minutes at 40', 3 at 25-30', and 4+ minutes at "safety stop" depths. If my loading is mostly in the faster tissues (coming up directly from deeper dive), then I bias things a bit towards the deeper stops. If heaviest loading is in the medium speed compartments (such as from a 50 minute air dive to 60' flat bottom), the everything get moved a bit shallower to 40' / 25' to 20' / and 15' to 5'.
3. Nominal ascent rate between stops is 30fpm, but I don't sweat it too much. How I really control my overall ascent rate is by looking at my computer, taking the current runtime, rounding it up to the next minute (doesn't show seconds), and adding to it my total ascent time (typically 6 to 9 minutes). That give me the end time of my 20-8' safety stop/glide. The end of my 1st stop is 1 or 2 minutes, plus ascent time to 40' or 50'. End time for my second stop is obviously between those two times, and is closer to the 1st stop ending time than the surfacing time.
All of this may sound very complicated, but you will be surprised at how easily it all comes together if you try it the next few times you start an ascent. After a while, you really just have to remember starting time, what you have chosen for surfacing time, and after than you just glance at your computer or bottom timer and you pretty much can automatically tell if you are at the depth you should be for that runtime.
---------------------
ROCK BOTTOM
As I posted about 3 years ago, this extend ascent requires about the same amount of air that is required for an emergency problem solving + ascent with a panicked diver, so there is no need to increase rock bottom numbers to account for the slow ascent and extra stops.
I just use the simple 100psi per 10' of depth, but never less than 700psi. This is true rock bottom, not just a "let's start ascent somewhere around this psi". Rarely do I ever get to rock bottom.
-----------------------
The title of the thread is "Exploration Dives Without A Computer". My method could be used without a computer, but in reality is more along the line of how to intelligently dive WITH a computer.
I suspect that there are other divers out there that have developed or evolved similar methods of controlling their profiles, but have not seen anyone post their methods.
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