Full cave and Nitrox?

[Rush]

Stage bottles are typically worn on the left side to better facilitate streamlining and one hand valve management. Wearing stage or deco bottles on both sides limits flexibility and gives you an awkward muscleman posture. If you use a DPV, bottles on the left side facilitate better control of the DPV. I was curious about this, too, as my IANTD training conflicted with the DIR philosophy. My cenote guide in Mexico was a GUE/DIR diver and he cleared this all up for me.

 

[Duncan Price]

Aviatrr once bubbled...

I remember a while back Duane outlined a DIR sidemount configuration, and I know you had one of those rigs...though I don't know if you used it yourself or sold it for somebody else. Now I don't recall the total description, but one thing that jumped out at me was that wing inflation was strictly oral - no inflator hose attached to the power inflator. Why? Also, IIRC, the procedure was to breathe strictly off of stages(correct me if I'm remembering this wrong) and not the primary bottles.....is this at all times, or just scootering? Why? If you're diving in sidemount passages that are big enough to allow you to carry stages, they would probably be doable backmount.

I dive sidemount almost exclusively. Single stages are carried chest mounted down the centre of the body. 2 stages are carried bilaterally, the third goes in the middle. Never needed to dive four stages yet...

Our stages are basically the same as our primary sidemounts - all steel because you can throw them around down caves - I mean carry them through boulders, down drops etc etc. Often they are smaller tanks that you'd use sidemounted for shorter dives. Often we are not breathing our stages during the dive but carrying them through sumps for use further into the cave. I've scootered with bilateral stages no problem - the prop wash runs beneath and down the centre of the body.

The sort of cave diving I do is way different than "Florida spring plopping". We use our drysuits for bouyancy and don't wear a wing. We wear helmets beacuse we are cavers and they protect our skulls whilst caving. Our lights go on our helmets because we can keep our hands free. Its all down to expediency rather than what is right or wrong.

Duncan

 

[Aviatrr]

Stage bottles are typically worn on the left side to better facilitate streamlining and one hand valve management.

I don't agree with that. I am much more streamlined with a stage on each side than two on my left side. One hand valve management? What's that supposed to mean? That all valves can be manipulated with the same hand? Doesn't make sense to me, unless scootering....but I don't manipulate my valves while scootering anyways. If I need to shut one down, I'll take my hand off the scooter and do so.

If you use a DPV, bottles on the left side facilitate better control of the DPV.

Again, I don't agree. I've tried both ways, and prefer the bilateral method. Rig the stages properly(and scooter properly) and the prop wash will remain clear of bottles on both sides. WHY does it supposedly facilitate better control?

Mike

 

[Rush]

I guess you would have to ask JJ, since he wrote the book on these fundamentals of DIR. I can only assume that he has the data that would support these methods as being sound diving practices. One reason that the stage or deco bottles are worn on the left side is that DIR configuration calls for the cannister light to be hip mounted on your right side, therefore they carry the stage bottles on the left side so as to not interfere with the cannister light. Also, with the bottles on the left hand side, the right arm is always unencumbered, allowing for more flexibility for working through smaller areas with stage bottles or driving a DPV.

Again, my prior training conflicted with DIR, but the further I go into learning the DIR, the more things I find make sense to me, or are more comfortable. At this point, I do not agree 100% with everything that DIR does. I, like you, don't seem to have a problem manipulating my stage or deco bottle valves regardless of which side they are on. So, as I am a newbie to DIR, I am not qualified to answer specifically why the prescribed positioning is superior. I began to learn DIR to see what best practices I might pick up. One thing I dislike about DIR is the superior attitude some of the divers have. That is one trait that I REFUSE to adopt.

 

[roakey]

Ok, here's a regurgitation of what I've read about stage bottles on one side over the years. If you want to cross-examine what I'm writing you'll have to contact Jablonski or Irvine.

First off, putting stage bottles on the right interferes with the deployment of the long hose. Though BMU some of the WKPP setup divers do have a D ring on their right side behind the canister light where they do put bottles, but only the neck boltsnap is attached, and they're the very first bottles to be dropped.

The problem with drag is not with prop wash but equipment hanging out of the slipstream created by the scooter. The blunt nose of the Gavin/SS/whatever creates an area behind it where the diver can draft like a racecar. Bottles on both sides are too wide to fit in this slipstream and the drag created by the bottles "sticking out" into the static water slow the diver down.

Note that the increases realized by putting the bottles are not huge, but it adds up. An increase of, say, 5fpm amount to almost a thousand more feet of cave explored in a three-hour penetration.

The configuration was not arrived at without considerable experimentation. "Drag races" between different configurations while nullifying scooter differences have been performed, as well as "time trials" - timing how long it takes a certain configuration to go a certain distance. My favorite is that the WKKP/Irving/whoever did some testing in the haloclines in Mexico to see what the scooter's slipstream looked like and to identify where the equipment was sticking outside the slipstream.

Roak

 

[scubaguy]

I think its a good idea to be Advanced Nitrox, our Instructor here had us do Advanced Nitrox and Decompression Procedures before we started any cave training. It wasnt absolutly nessecary for every Dive but it was nice to have a good background if the &*%^$ hit the fan.
I guess it depends on where you dive, We dive in Missouri and all the Caves are Deep,so i guess all that is important.
anyway thats my 2 cents.