I just took GUE Fundies, and I am making some major changes ! :-)

[TSandM]

Dan, having Bob watching would ruin my SAC rate too, I'm sure!

 

[danvolker]

dan how about when shootin vid, I review yesterdays dive a little bit ago and a sealion buzzed around and I noticed I just kept sucking, I breathe in and a little more and a little more. The vid told me that and not sure if it was buoyancy or just not letting bubbles out as sealions like to bite bubbles. I mean running vid especially when in the 5th and 6th atm's, I use breathing for buoyancy to keep vid quality and add air fewer times for this reason.

Yeah..when we are shooting, we do NOT want to take our hands of the camera to pull dump valve or to inflate....we need rock steady camera, both hands on while shooting. Most clips wont run more than 2 or 3 minutes.

 

[VooDooGasMan]

And that is why you have no real difference in sac rate also, I think.

 

[lamont]

And this gets to how hard it is to convey ideas like this on a discussion thread. My expectation, is that most cave divers with good bouyancy and trim, make their wing inflation adjustments to the lung volume they plan of averaging throughout the dive, and to the breathing rate...getting an average swing up and down, and the wing needs to have inflation adjusted to this average....I do NOT think OW divers think about this, or even are aware of such a thing.

Well, you have to do it on the fly. You need enough gas in your wing to float your tanks so that if you empty your breathing gas you won't get pinned against the roof of the cave and have gas in the wing to dump in that instance. So you need to have some gas in the wing, and that means that the wing (and drysuit) will need to be adjusted continuously in order to keep breathing normally out of the middle of your lung volume. Its a constant adjustment throughout the whole dive.

I absolutely agree that doing too much lung boyancy wastes gas....while normally I would never be guilty of this in the ocean, during Fundies open water dives with drills constant throughout, I WAS guilty of this overuse of lungs for control, and my sac rate became very average, instead of very low as usual.
I'll blame this on performance anxiety having Bob watching

Right, the effect on your SAC rate from overuse of lung control is what I was primarily talking about.

The whole story of how Bob took me from just using my lungs to also using my wing and my trim and fins for buoyancy control has a lot more elements to it though.

 

[Blue Sparkle]

My expectation, is that most cave divers with good bouyancy and trim, make their wing inflation adjustments to the lung volume they plan of averaging throughout the dive, and to the breathing rate...getting an average swing up and down, and the wing needs to have inflation adjusted to this average....I do NOT think OW divers think about this, or even are aware of such a thing.

Edited to add: Before you read this, I just got to thinking, and I realized that what I'm addressing may not even be what you are talking about, but rather maybe your point is about some part of buoyancy that I don't even understand yet, thus proving your point. If so, then please pardon my post (which I'll leave here anyway).

******
This seems to broad to me. I speak as an OW diver. I won't even begin to say that my buoyancy was polished at dive 20 (or even now), but I will say that by then I had figured out that one uses the BC to set up their basic buoyancy and then lungs for fine adjustments. I'm sure I don't do it perfectly even now, and I probably sometimes over-use my lungs compared to the ideal; but I don't either JUST use my lungs or JUST use my BC.

Rather, I get the BC close, then use lungs a bit, and then if/when the lung part starts to become too "obvious" (i.e. too much at top or bottom of lungs), I adjust the BC to get myself back to "the middle" again. I'm pretty sure usual buddy does the same thing (it just seems logical?), and I can't believe we were that special, in the group of OW divers -- especially in our <25 "early" dives.

I can't speak for every OW diver - but that's what I'm saying: I find it hard to believe that "OW divers," as a group, don't "know" or think about this at all (?). My early dive training was about as mediocre as it gets, but just diving and working on buoyancy outside of any class made the BC/lung relationship reasonably clear (granted, most of my dives have been in "easy buoyancy" Florida, where a 5mm suit is the most extreme; but then that's the area you are speaking of as well).

Blue Sparkle

 

[dumpsterDiver]

One of these days you will decide to grace us with your presence on a dive....and you will see I am not giving up on swimming at "cruising pace" or "spearfishing pace"....I do plan on being in many penetration environments, in which I will need the ability to stop and be without movement....

Even in doubles and with jets on, I sincerely doubt anyone, even you, will complain about my "pace"


p.s.
We are planning on going out on Narcosis this afternoon, if you would like to join us !

Thanks Dan. So are you giving up the big fins and gonna go back to jet fins now?

 

[lamont]

Edited to add: Before you read this, I just got to thinking, and I realized that what I'm addressing may not even be what you are talking about, but rather maybe your point is about some part of buoyancy that I don't even understand yet, thus proving your point. If so, then please pardon my post (which I'll leave here anyway).

******
This seems to broad to me. I speak as an OW diver. I won't even begin to say that my buoyancy was polished at dive 20 (or even now), but I will say that by then I had figured out that one uses the BC to set up their basic buoyancy and then lungs for fine adjustments. I'm sure I don't do it perfectly even now, and I probably sometimes over-use my lungs compared to the ideal; but I don't either JUST use my lungs or JUST use my BC.

Rather, I get the BC close, then use lungs a bit, and then if/when the lung part starts to become too "obvious" (i.e. too much at top or bottom of lungs), I adjust the BC to get myself back to "the middle" again. I'm pretty sure usual buddy does the same thing (it just seems logical?), and I can't believe we were that special, in the group of OW divers -- especially in our <25 "early" dives.

I can't speak for every OW diver - but that's what I'm saying: I find it hard to believe that "OW divers," as a group, don't "know" or think about this at all (?). My early dive training was about as mediocre as it gets, but just diving and working on buoyancy outside of any class made the BC/lung relationship reasonably clear (granted, most of my dives have been in "easy buoyancy" Florida, where a 5mm suit is the most extreme; but then that's the area you are speaking of as well).

Blue Sparkle

My OW training wasn't particularly mediocre. Around dive #25 I took fundies and I was diving as DIR/GUE as I could manage from the start. I understood buoyancy control as well as you did and as well as you likely do now certainly around dive 100.

There's another level of buoyancy control which Bob showed me in a couple of classes I took from him, but I didn't understand it until I actually took cave and started running reel into cave, and started technical diving deeper. You need to be adjusting your buoyancy control a lot more before it becomes "obvious" for one thing. Swimming around at 60 feet, relatively unstressed, though, it just doesn't matter to that degree.

So, yes, I agree with Dan that OW divers as a class don't know and largely don't care about what we're talking about.

(And actually probably the majority of technical and cave divers these days don't know either)

 

[Mayor]

Dan, having Bob watching would ruin my SAC rate too, I'm sure!

I don't know for sure if it was the camera or being in the water with yoda but we did suck some air at 25ft.

 

[Blue Sparkle]

Thanks, lamont. Sounds like my "second thought" (in my edit) was correct then, and there is a whole 'nother level. Of course now I want to know about it

 

[Scott L]

I think it is sad. You are getting old.

Not so long ago you were all about efficiency and minimal drag and the ability to move efficently in high currents. I even remember a Volkerism about being able to keep up with dolphins....

One of these days you will decide to grace us with your presence on a dive....and you will see I am not giving up on swimming at "cruising pace" or "spearfishing pace"....I do plan on being in many penetration environments, in which I will need the ability to stop and be without movement....
Even in doubles and with jets on, I sincerely doubt anyone, even you, will complain about my "pace"


p.s.
We are planning on going out on Narcosis this afternoon, if you would like to join us !

I doubt you would ever see DD on a reputable charter boat. They check for licenses, poaching, Etc., Etc.