How do I improve my air consumption?

[Rick Murchison]

Hmmm... interesting recommendations... not practical in many cases in the real world of diving. Getting out of the water (climbing the ladder) in full gear is the norm on many if not most commercial diving boats. Likewise, moving tanks around. The fact that Dr. Deco's research indicates these are not "good" lends yet more credibility to the "dive conservatively" advice that accompanies all diving computers and is recommended by all training agencies.
Rick

 

[Dr Deco]

Hello Rick and other readers:

Your point about the norm in recreational diving is understood. What I am doing here is making an attempt to introduce some thoughts that may, in the future, change some of the common dive practices that might be less than optimal.

Since all decompressions to altitude (what occurs operationally at NASA) commence from sea level (with the same gas loadings in all people), the only variations among individuals can be in inert gas elimination or nucleation (= tissue microbubbles). These altitude scenarios have allowed us to examine the important question of nucleation and the physical activity that provokes the bubble formation in the first place. This is important to NASA operations, since these occur in null gravity (0-g) conditions and change the risk of decompression sickness during EVA to a considerable degree.

The fallout of this for the recreation dive community is a "discovery," in quantitative terms, of what activities add to DCS risk beyond the obvious ones of gas loadings. Thus, where possible, I attempt to inform the dive community and hope that some practices might change to increase safety. People tell me that some boat operators do have exits from the water on platforms at the end of the boat, and that they do assist divers out of the water (i.e., without full gear).

I hope that this material is of value to some divers since it is your tax money that pays for this research. It is a small spin off from the space program that you can apply to a part of your life today -- without ever leaving earth!

Good diving !
_____________________
[sp]Michael R. Powell, Ph.D. a.k.a. Dr. Deco

 

[King_Neptune]

Rick M,

Originally posted by Rick...

... not practical in many cases in the real world of diving. Getting out of the water (climbing the ladder) in full gear is the norm on many if not most commercial diving boats.

Well, shame on them ... I have logged literally 1000's of dives, been diving with 100's upon 100's of different people or "buddies" if you will. You would be better off going "snipe" hunting on Santa Claus' property with the Easter bunny than you would trying to find a single person that I have been diving with that I didn't either reach an arm out to grab their gear or lift their gear up to them if they exited the water before me.

Although I can, I am having a hard time remembering a dive boat where a divemaster wasn't on hand to help divers exit the water. If you're paying for a boat dive trip somewhere what are you paying for? A taxi and nothing more nothing less? Is there a Boat Captain and Divemaster there? What are they doing? Smoking a stoggie and sipping a martini? If they care much about their boat and any repeated business they should be doing what you paid them for... To make sure you have as safe and as enjoyable time as possible! If there is not a dive platform off the end of the boat I would think the Captain nutts to sit there and just watch as everyone tries to clunk their way up the side and ding this and that as they stumble around.

Where is your buddy? Aren't they helping you? Aren't you helping them? Is this a WWF cage match or buddies diving together?

If these chartered trips are a "everyone fend for themself" then I would have to question the service, and yes I mean I would literally QUESTION them! Call them on it, ask for assistance. No one is so studly of a "Joe Diver" that they are too good to help out.

Maybe I'm the oddball here but if everyone on a trip I was with had to do everything themself I would be embarrased and ashamed. Men and women alike, but especially for the ladies. Not because of anything like "they are the weaker sex" as I believe that is crap, but because there aren't many women out there that are as big or as strong as I am, but if they are you can be darn skippy that I will have no trouble asking for their helping hand.

I kind of thought that was the whole purpose behind "buddy diving". According to what Dr Deco has said, all of this would fall into the category of "safety", and as far as I know the concept of buddy diving has its foundation in the promotion of "Safe Diving".

=-)

 

[Rick Murchison]

Many boats - especially re-rigged crew boats converted from the heyday of oil in the Gulf of Mexico, have long angled ladders (about like a ship's ladder) off the stern that don't lend temsleves to more than one person on the ladder at a time, nor to hauling gear aboard after shucking it on the surface. Common practice (and the safest)is to take your fins off at the ladder and climb the ladder in full gear - the next diver in line stays well clear of the ladder until you're aboard just in case you should fall back in - avoiding the old tank-in-the-noggin syndrome. This procedure on these boats isn't something dreamed up overnight, and is not the result of carelessness or neglect or laziness on the part of the boat's crew, but rather the safest and most efficient method of reboarding these boats, developed over years of experience.
Rick

 

[King_Neptune]

Rick M,

I understand your point, but then again the there was a time when it was believed that if you were sick the right thing to do was to drain you of your blood, I mean that's where the sickness is right? And this was not "something dreamed up overnight" nor was it "the result of carelessness or neglect or laziness on the part of the"... doctors of that time, this was the SCIENCE of the day, and who is gonna argue with that? Last time you went to the doctors did they pump you dry? I mean, this was "developed over years of experience" and "the safest and most efficient method of..." Ever need stiches, broken a bone, did they amputate, etc? I think you get my point.

Gee, it used to be THE WAY it was done to stand in a straight line in obnoxious bright red on the front lines of battle and take turns shooting at each other! DOH, someone PLEASE shake the hand of the Indian that taught us that was about as stupid as it gets!

Times have changed and we know better or know how to better handle these things. I myself have been on many more Ladder boats than Platform boat also, and common sense told us to hand up our weight belts and then slip out of our BC's and hand them up. To be honest, that's the way I've seen most all of the Rescue and DiveMaster classes taught. Now, maybe that's a PADI, NAUI, PDIC and BSAC thing as those were the classes I refer to but I thought they were more of a CAPTAINS decree. And yes, MANY of my boat dives were done in the Gulf of Mexico too, especially as I was stationed in many places like Texas, Louisana, Florida, etc, etc...

But beyond any bickering over what is considered "the way it is done" we are lucky enough to have someone with the Extremely Honorable credentials that Dr Deco has, that can shed some light on "maybe the way it is done is not so great after all". Personally, I don't have my PhD, nor have I spent years of my life working for NASA in this field or worked with DAN or the NAVY etc etc .. so I can't help but listen with the biggest gratefull ears I can and if something is presented that seems to go against what is the "norm" then maybe we need to take another look at the "norm".

Remember, the knowledge he shares with us is what YOUR (USA) tax dollars are paying for. I personally can only continue to thank him for sharing these things with us. Just ask "cynsearles@hotmail.com" (from Canada) what she thinks about what he has to say.

=-)

 

[Rick Murchison]

C'mon down. We welcome your vast experience and suggested improvements.
Rick

 

[King_Neptune]

Rick,

Question for you ... Are you refering to what is commonly refered to as "Cattle Boat" charters?

Ya know, the ones that what is "most efficient" is really what is "most profitable"...

your thoughts ....

=-)

 

[Beachman]

I dive with commercial operators and I dive my own boat. My experience with commercial operators is that a DM or Mate is normally on the platform to help, particularly to take off fins. I personally don't like anyone messing with my gear, either to hand it up ( on a boat with 20 divers, how do they handle it?) or to take it and change my tank out (this is a favor?). But if the operation sets the rules, and generally I can live with them for the good of the order, I try to comply.

I don't care if your diving a boat or shore diving, when not in the water, when entering or exiting with full gear, it's a strenuous experience. That's why I do everything I can think of to make sure it's the least strenuous that it can be.

On my own boat, I have a tether line dangling near the boat where the tag line is tied off. Of course, there's only 4 divers normally, and no one on board to help. Makes sense to get out of your gear in the water 'cause it's easier.

On most commercial operations, their primary concern is getting everyone out of the water when they want, or need to get out.....fast and efficiently. You can have 20-25 divers sometimes. Generally the folks down there have many different experience levels. Some might even freak at the idea of doffing their BC in the water! The reason fins are removed on the platform (either in the water, which I prefer, or by the DM or mate) is to prevent attempting to walk in a close environment on a rolling boat with full gear and fins. Most folks can handle the full gear, but not necessarily with fins.

What do you do if everyone on the hang bar is taking turns, waiting and watching in a 3 knot current, and some fool can't figure out how to release their BC. Does everyone wait when this jerk could have been out of the water in 30 seconds if the rule wasn't "take off your BC"? Heck, I say get them out of the water ASAP...by the neck, if necessary.

I think it's very necessary to listen to folks like Dr. Deco and understand the expanding knowledge of the physiology of high pressure, and low pressure, environments on the human body. Maybe that way eventually the training and procedures of diving will change to the point that the practical issues I've raised above will be "non-issues" because everyone will understand the associated risks and comply accordingly with training and accepted practice.

Nevertheless, we are where we are today and us recreational types have to deal with what is best for the most folks. Personally, I really have no problem climbing a ladder with my full gear, having someone service my fins if they want, and keeping my own gear to myself as I stagger to my slot on a commercial boat.

JMHO, and DSAO

 

[Rick Murchison]

yep. cattle boats.. and some live-aboards (especially the cheap ones like I can afford).. But I've been aboard cattle boats with water-level dive platforms too.
Another type diving where hauling your own gear is necessary is shore diving. My point in all this is that if you dive then it is often impractical to avoid honking around heavy stuff, so conservatism with the computer/dive tables is even more important than if we *could* dive without heavy exertion. Interestingly, I do my heaviest lifting around my most intense (from a decompression standpoint) diving - caving - doubles, stage bottles etc. We take it *real slow* but there's no avoiding the manual labor of moving the gear to and from the entry point.
Rick

 

[Mario S Caner]

I for one am very happy that a respected individual such as Dr Powell can find the time to contribute to this forum. I look forward to reading your words of wisdom, and hopefuly retaining all that I possibly can.

Fellow divers: It's through divers like us, collectively, diligently working that will enable us to improve the community as a whole. There's a saying that I beleive in: "a closed mouth doesn't get fed" think about it, if we turn the other cheek to minor irritations with the way certain things are done in the community, how can we possibly improve it?

Sea you in the Deep Blue,
Mario