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Dude
SFN Die Hard
USA
6891 Posts |
 Posted - 04/29/2007 : 20:44:35 [Permalink]
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filthy said:
quote:
Between medical checks, we played dime-a-game, penny-a-point, round-robin cribbage through the whole thing. I lost something like four bucks and learned to hate cribbage.
Sounds like not fun 
The Navy, as far as I know, keeps their tables up to date with recent research (they do their own fair share too).
I'd feel confident using them if all of my dive computers went on the fritz.
The CCR rig I trained on had an amazing dive computer. You can use it to plan your dive, quadruple redundant O2 sensors to maintain a set pO2, and it also calculates your deco obligations based on your actual dive profile as opposed to your planned profile. So if you screwed up and stayed at 300fsw for 7 minutes, when you planned 5, it automatically adjusts your deco stops. (the only drawback is that you are locked into its dive profiles and deco tables, or it will lock down the system when you surface)
With straight up heliox your deco obligation isn't to bad in most cases. IIRC my last 300foot dive (I haven't kept up lately, out of practice, and this shit is ridiculously expensive too) lasted about 100 minutes with a 5 min max time at 300fsw, with the CCR.
(CCR = closed circuit rebreather, for those who may be wondering.)
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 04/30/2007 : 01:14:10 [Permalink]
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quote:
Originally posted by Dude
filthy said:
quote:
Between medical checks, we played dime-a-game, penny-a-point, round-robin cribbage through the whole thing. I lost something like four bucks and learned to hate cribbage.
Sounds like not fun
The Navy, as far as I know, keeps their tables up to date with recent research (they do their own fair share too).
I'd feel confident using them if all of my dive computers went on the fritz.
The CCR rig I trained on had an amazing dive computer. You can use it to plan your dive, quadruple redundant O2 sensors to maintain a set pO2, and it also calculates your deco obligations based on your actual dive profile as opposed to your planned profile. So if you screwed up and stayed at 300fsw for 7 minutes, when you planned 5, it automatically adjusts your deco stops. (the only drawback is that you are locked into its dive profiles and deco tables, or it will lock down the system when you surface)
With straight up heliox your deco obligation isn't to bad in most cases. IIRC my last 300foot dive (I haven't kept up lately, out of practice, and this shit is ridiculously expensive too) lasted about 100 minutes with a 5 min max time at 300fsw, with the CCR.
(CCR = closed circuit rebreather, for those who may be wondering.)
Yeesh, what a dinosaur I am! All we had was an ill-tempered Master Diver, a couple of stop watches, and The Tables. The great bulk of my work was at way less than 100' and done in a Jack Browne rig (full-face mask supplied by a compressor on the surface). That might sound pretty cushy, but far more often than not, the job was in a harbor or river. Didn't get to see much -- hell, we didn't get to see anything. The water was so dark with silt (and other stuff that doesn't bear mentioning) that even lights were useless. We did everything by touch, and looking back through the slightly foggy lens of nostalga, we did some damned good work under some very trying conditions. Sometimes, that water was cold enough that, with the deep rig, we used a wet suit for underwear.
When that bomb went in, my ship, the Holland -- a Submarine Tender -- was permenantly stationed in Rota, Spain -- the only gravy assignment the Navy ever gave me. One day the Master came down to the Diver's Locker and told us to start splitting and mixing gas -- this is done with bottled O2 and helium, and a compressor, if anyone wants to know. As soon as he said that and told us why, we knew we were in trouble. We also knew at least part of the fix; a shipmate and I went over to the base Ship's Store and bought every box of Kotex they had, much to the astonishment, and hilarity, of all. We sewed these to the shoulders of our underwear to prevent "suit chancres." A suit chancre is a raw abrasion sore caused by the helmet's breast plate rubbing on the shoulders, usually aquired when entering or leaving the water. Once you have them, they won't heal until well after the job is over. Needless to say, we were very protective of our padded underwear because those things hurt. A pair of Kotex was usually good for one to four dives before becoming too thin.
I've been away from it for many years now, and the technology has slipped past me. Like everything else these days, I suppose, the computer has taken over..... 
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist! 
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 04/30/2007 : 14:29:20 [Permalink]
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filthy said:
quote:
I've been away from it for many years now, and the technology has slipped past me. Like everything else these days, I suppose, the computer has taken over.....
Oh yeah. Most recreational dive operators will not let people dive from their boats unless they are using some sort of computer these days. Everyone learns how to use tables still, but they are generally used as backup. And they just tell people to surface and return to the boat if their computer fails on a dive...
For recreational diving they are great. I have a couple that I use, one is a fully integrated depth gauge, tank pressure gague, and dive computer. I plug in my gas mix (anything from compressed air to 50% oxygen) and the computer sets the depth/time limits, I just jump in and swim around. As long as I stay within what the computer tells me, I'm diving inside the no-deco and max O2 limits.
They make it easy to plan a dive, and stay inside your plan while diving.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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Dave W.
Info Junkie
USA
26020 Posts |
Posted - 04/30/2007 : 14:48:29 [Permalink]
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Not too long ago, I had a temporary supervisor at work tell me that he had logged 12,000 dives. By my calculations, that's a dive per day, every day, for nearly 33 years. Now this guy is in his early 50s, tops, so even taking off weekends from this busy schedule pushes the year required to almost 46, so he would have had to be diving in his single-digit years. To top it off, he spent years in the Army, an organization not exactly known for their strict daily diving schedules.
Perhaps he intended to say 12,000 hours, but even at 3 hours per dive, on average, that's still 11 years of daily diving to rack up that much time.
But he specifically said - several times - "12,000," even if I can't tell whether he meant dives or hours. And he was specifically taking about SCUBA diving. From the people who know diving, here, how generous must one be for this guy's claim(s) to be credible?
Second, would daily diving for long periods (years) take a physical toll even if one stayed within the limits imposed by tables or computers? |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Hawks
SFN Regular
Canada
1383 Posts |
Posted - 04/30/2007 : 15:14:08 [Permalink]
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| Not to brag or anything, but in about two weeks time I'll be going on a four-day live-aboard dive drip on the Great Barrier reef. It's hammer-head season. Maybe the odd manta-ray? Who knows what will show up?! |
METHINKS IT IS LIKE A WEASEL
It's a small, off-duty czechoslovakian traffic warden! |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 04/30/2007 : 16:54:14 [Permalink]
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quote:
Originally posted by Dave W.
Not too long ago, I had a temporary supervisor at work tell me that he had logged 12,000 dives. By my calculations, that's a dive per day, every day, for nearly 33 years. Now this guy is in his early 50s, tops, so even taking off weekends from this busy schedule pushes the year required to almost 46, so he would have had to be diving in his single-digit years. To top it off, he spent years in the Army, an organization not exactly known for their strict daily diving schedules.
Perhaps he intended to say 12,000 hours, but even at 3 hours per dive, on average, that's still 11 years of daily diving to rack up that much time.
But he specifically said - several times - "12,000," even if I can't tell whether he meant dives or hours. And he was specifically taking about SCUBA diving. From the people who know diving, here, how generous must one be for this guy's claim(s) to be credible?
Second, would daily diving for long periods (years) take a physical toll even if one stayed within the limits imposed by tables or computers?
I'm not a SCUBA diver and although qualified for it, I really never was. Also, I don't know much about computers. But I think he was talking out his ass. I've been on salvage jobs, diving every day for a couple of weeks at a stretch, and what happens is that you simply burn out. It takes a lot of energy to function underwater and that is multiplied by temperature. Even the warmest sea water is cooler than body temperature, and it requires energy just to keep warm. Even wet suits will fail in due course -- and I can tell you a little trick to considerably lengthen your stay time in a wet suit, but I won't 'cause it's nasty.
Figger it out yet? 
The Navy was pretty smart about this. Whenever possible, they would put a large enough crew on it that you could get a couple days break -- tending other divers, mostly. Which was how all the First Class divers aboard my ship got press-ganged into bomb-hunting.
And we had a little trick to get out of diving: on long jobs, many of us acquired minor embolisms after a little time. We'd simply cough good and hard, and spit a little blood over the side when the diving officer, not the Master Diver, was looking. That'd usually keep us dry for a day or two, when we'd be miraculously cured and ready to go back to work.
There is no way that this guy did, what, 12,000 dives in 33 years unless he had a deep bathtub.
Don't know how it is now, but the Army had at least a few divers during the Korea years.
Hawks: quote:
Not to brag or anything, but in about two weeks time I'll be going on a four-day live-aboard dive drip on the Great Barrier reef. It's hammer-head season. Maybe the odd manta-ray? Who knows what will show up?!
Now there's a trip that even I would don some SCUBA gear for! 
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 04/30/2007 : 17:12:38 [Permalink]
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Dave_W said:
quote:
But he specifically said - several times - "12,000," even if I can't tell whether he meant dives or hours. And he was specifically taking about SCUBA diving. From the people who know diving, here, how generous must one be for this guy's claim(s) to be credible?
I'd accept 1000-2000 as a realistic number of dives for a person to log in a decade of active diving. You can get in 3-5 shallow water dives (less than 60feet) in a full day of diving.
I can't think of anyone who would want to dive every day, especially on a repeat dive profile, for an extended time. That kind of thing is what you do on a dive vacation, for about 4 or 5 days, and most people are exhausted by the end of a trip like that.
But lets examine his claim from a financial standpoint.
1 tank fill- ~$7 for air (if you own your own tanks)
Annual gear maintenance for 1 regulator and BC- ~$150
Annual maintencance for scuba cylinders- ~$25 each
5 year mandatory pressure test for scuba cylinders- ~$50 each
Annual misc expenses for consumable items for an active diver (like mask defogger, sunscreen, wetsuit cleaner, etc) is- ~$200
If he has a place where he can dive for free, then we can ignore this next part.
The cost of diving from a boat or use of someone elses property for a land based dive (like fresh water springs) is ~$30/dive. Alternately, he could own his own boat, but anything capable of reaching coastal dive sites is probably going to cost you, personally, more than an average of $30 a dive.
I'll ignore transportation expenses, but you'd have to add them in if he doesn't live in close proximity to someplace to dive.
Sooo.... for 12,000 dives over (we'll assume 30 years, say he started at 22 and is now 52) for an average of 400 dives a year:
Air fills- $84,000 or $2800 a year
Dives- $360,000 or $12,000 a year
Gear/Tank maint- $6000 or $200 a year
Pressure tests- $300
Misc expenses- $6000 or $200 a year
Total- $456,300 or $15,230 a year
I would say that 400 dives a year is certainly phisically possible, but this is a number of dives that you'd expect out of a person who is a dive instructor or dive boat crew. And you wouldn't expect them to be sustaining this level of diving every year for 30 years solid.
I'd say that a person who has a job outside of dive services is not going to be logging 400 dives a year.
Personally I would consider 100 a year to be a lot of diving, even for a sport-tech diver. I don't keep up with my dive logging as well as I should (most divers don't), but I'd say that my most active diving year ever only involved about 150 dives. And that year I, and friends, went almost every week on either a boat (to spearfish) or to various freshwater springs in FL over the winter.
I know people who I would believe if they said they had 12,000 dives, but every one of them works in some dive service capacity, most of them are atleast in their 50s (one guy is in his mid 70s), and diving is their career.
Hawks said:
quote:
Not to brag or anything, but in about two weeks time I'll be going on a four-day live-aboard dive trip on the Great Barrier reef. It's hammer-head season. Maybe the odd manta-ray? Who knows what will show up?!
Sweet!
Some day before I die, and hopefully before the reefs die, I want to get over there for a liveaboard dive trip. I'm betting you will have a blast.
Take some pics and post them up for us!
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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| Edited by - Dude on 04/30/2007 17:23:30 |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 04/30/2007 : 17:20:07 [Permalink]
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Sharks...
I'll tell you have to improve your odds of seeing a hammerhead.
Take a bottle of water, put it in your BC pocket.
When you are in a good spot, someplace you might have a shot at seeing the big sharks, like on a wall....
Hold the bottle upsidedown, use your octo and put dribble some air into it, till it is atleast half air. Make sure the bottle isn't tight, and put the lid back on.
Hold it in both hands and squeeze one hand at a time, to make noise. The crinkling plastic makes a noise that sounds like some fish in distress.
Have used that to call in hammerheads on the south wall of Cayman Brac.
Obviously, if you see the shark, stop making the noise.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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Dave W.
Info Junkie
USA
26020 Posts |
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Hawks
SFN Regular
Canada
1383 Posts |
Posted - 04/30/2007 : 18:29:05 [Permalink]
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quote:
From the people who know diving, here, how generous must one be for this guy's claim(s) to be credible?
I wouldn't find it impossible. I was working as a dive guide in Thailand (Phi-phi island that was subsequently flooded in a very famous tsunami) and logged some 150 dives in about 4 months. Some of these were so-called "discovery dives" (take a noobie down to about 5 meters and let them splash a bit) after/instead of the usual two dives per day. Since I got a bit bored of diving for a while after this, I didn't sustain the same rate, but some of the other guys had been doing the same stuff for YEARS.
In this sort of situation, cost wouldn't be a problem (however, only getting paid enough to live in an ant-infested "bungalow" with no running water and only being able to afford to eat fried rice can be counted as a cost, I suppose).
But then, as Dude said: "I'd say that a person who has a job outside of dive services is not going to be logging 400 dives a year. ". I'd probably agree with this.
quote:
Dude wrote:
Have used that to call in hammerheads on the south wall of Cayman Brac.
MIGHT try that. I want to see them - not fondle with them.
Cayman Brac, eh? I did a few dives of Grand Cayman (was promised a job as an instructor. However, when I arrived, the guy that promised me the job had been fired and it turned out that they didn't really need anyone. Bastard!). Diving was really good. Stingray city springs to mind.
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METHINKS IT IS LIKE A WEASEL
It's a small, off-duty czechoslovakian traffic warden! |
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JohnOAS
SFN Regular
Australia
800 Posts |
Posted - 04/30/2007 : 19:49:38 [Permalink]
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quote:
Originally posted by Dude
Sharks...
Obviously, if you see the shark, stop making the noise.
That's fantastic. I know that in your complete context, it makes sense, but it does sound rather comical. It'd make a nice epitaph.
"He saw the shark, but didn't stop making the noise."
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John's just this guy, you know. |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 04/30/2007 : 20:54:13 [Permalink]
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John said:
quote:
That's fantastic. I know that in your complete context, it makes sense, but it does sound rather comical. It'd make a nice epitaph.
I was going for funny
The sound really does, in my experience, attract sharks though.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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HalfMooner
Dingaling
Philippines
15831 Posts |
Posted - 05/01/2007 : 04:13:55 [Permalink]
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quote:
Originally posted by Dude
John said:
quote:
That's fantastic. I know that in your complete context, it makes sense, but it does sound rather comical. It'd make a nice epitaph.
I was going for funny
The sound really does, in my experience, attract sharks though.
And let that final sentence be part of the Darwin Awards entry.
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“Biology is just physics that has begun to smell bad.” —HalfMooner
Here's a link to Moonscape News, and one to its Archive. |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 05/01/2007 : 12:34:51 [Permalink]
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Back to the whole high grav environment thing...
Say that life does exist in such an environment, and that it has evolved to the macro scale and attained some degree of sentience.
What are the possible implications of this in a high G environment?
Well, as we know, objects accelerate faster. In response it seems plausible to say that life forms would be required to react faster than those on earth.
This seems to imply several things when compared to earth. Greater strength to withstand the increased gravity. Faster reaction speed to compensate for objects moving faster. If life has any sort of nervous system it seems the signals would have to be conducted at a higher speed to achieve the reaction times needed to survive in the increased acceleration.
The presence of some sort of central processing unit, analagous to the brain, and composed similarly to the peripheral nervous system of our alien life, seems safe to posit (assuming the presence of a sentient life form).
Would the same rules apply to this alien high G brain? Faster signals? And would that imply greater intelligence compared to earth species? Maybe greater computational capacity?
So would the consequences of high G evolution mean that a sentient being in such an environment would be faster, stronger, and smarter than earth life?
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 05/01/2007 : 13:21:57 [Permalink]
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I don't think that we know enough about the mechanics of evolution to even speculate about complex life forms in such an enviornment. But, stuff like that's never stopped anybody yet, so, here's a little of mine.
I think it's entirely possible that the most complex would be invertebrates, of sorts. My reasoning is that they are highly resilent and have been so successful here. Our own, first complex species were invertebrates in the seas, and some of those were the first to come ashore. Their decendents are with us today in the forms of spiders and scorpions among many, many others.
In the seas, the same holds up. Pressure doesn't affect crustations, mollusks and jellies much, and such as these would have an advantage over anything requiring bouyency ie: with a skeleton.
I think that most would be very strong, by our standards.
As for intelligence, <shrug> define intelligence.... Same for civilization. What is the definition of "is", eh? Our concepts of those matters might not be the same as their's.
Of course, I have no references to study, so I am probably full of shit. But there you have it; a little of it, anyway.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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Earthlike planet
