Why use aluminum doubles for ocean diving???

[WYDT]

JT2 once bubbled...
I don't understand why he would be in favor of using stages over steels, after all, aren't we supposed to keep it as simple as possible? I would think the simplest way would be to wear appropriate sized doubles so that you didn't have the added task of carrying and managing stages. I'm still confused .. I just don't see a good reason for carrying stages when diving dry if you could get the amount of gas needed by carrying larger steels.

I never said I couldn't handle 104's getting on a boat, I just said that they can be a beeotch when things get rough. I still use my 104's on any mix dive with drysuit and dive my AL80's when wet.

I think you guys are misunderstanding what I was talking about...

I'm talking about using stages with cavediving and (DPV)scootering...

I'll describe a typical dive...

DIR config... 104's, Drysuit, Gavin scooter, etc. 2 stages + O2 for deco (AL40)... add deco gas dependent on depth...

Stages are both on the left and O2 is dropped at 20ffw in the cave or cavern. Breathing stage 1.... use 1/2 + 200 of stage 1 then drop it. Go to stage 2 use 1/2 +200 then turn the dive. Use the other 1/2 of stage 2 getting back to stage 1. Go to stage 1 and use it the rest of the way out. Backgas is not touched.

Scootering in a cave requires MUCH different gas management than OW non-scootering. In the event of a total cluster the stages can be ditched and one can run slick for the door on backgas. There's more to it but that's the quick low down.

You want to go farther... add a stage. Carrying 3 stages is NOT hard at all when scootering and depending on depth one can get to 4000+ feet with only two. Ohh also any dive over ~3000ft requires a tow scooter for a team of 3 or each diver has a tow scooter for a team of 2.

NO way would I do a scooter dive on backgas only! I would do a wreckdive (limited penetration) with backgas only and proper deco gas in stages. All this would depend on the depth and current of course.

DSAO!

 

[WYDT]

WreckWriter once bubbled...
here we have a guy that drinks LOTS of Kool Aid

WW

 

[WreckWriter]

WYDT once bubbled...

I wonder if I could get my little avatar guy changed! Now if one of our artists can put a set of doubles on that guy.....

Tom

 

[MHK]

LUBOLD8431 once bubbled...
I BREATH my doubles... I use my stages for DECO... Why would you want to wear a set of doubles and then not use them??? Is it just a very large amount of safety or what??? I dont get that... I understand the rule of thirds, but not the rule of DONT BREATHE YOUR BACK GAS!!! and by the way, i use a set of OMS 112's for cave dives and wreck dives.... In new england, 4-6 foot seas is the NORM... i have ZERO problem with lifting my tanks out of the water... Maybe you guys should HIT THE GYM!!! Build up some muscles so you can use a REAL MAN's TANK.... by the way, even some of the WOMEN i dive with use STEEL tanks, and can lift them out of the water... ut:

Not to break up your GUE bashing to much, but a few small points that I thought I'd offer in case anyone was taking your posts seriously.

There is a difference between a stage bottle and a deco bottle and most use their stage bottle to extend distance or BT, whereas most use their deco bottle with elevated oxygen mixes to accelearate decompression. So perhaps they didn't teach you that difference in your classes, but some may know the difference and question why you would be breathing your *stage* bottle on deco.

As for not breathing back gas, again a common tool used for a variety of diving. Once you gain some experience in different environments you'll see this technique used often. I'll note the last time I dove the Doria in 1999, which is 100 miles off shore. You are out there for 3 days, they have no blending facilities on the charters so a common technique is to put a 10/70 in your back gas and then use a proper pre-blended mix in your *stage* bottle. You use the stage for the dive, keep the back gas for emergencies, and then if you use the back gas on a dive you can top it back off on the boat and still have a useable gas for the rest of the trip..

Again, I've just scanned a few of your posts and I'm confident that you know all of this stuff, so I thought I'd just offer a few ideas based on real life diving experiences, not some ill-advised classes ;-)

BTW, if you have any questions relating to GUE or DIR I'd be happy to answer them, and BTW I have no problem lifting my double 104's..

Later

 

[O-ring]

Would you dive double 80s on the doria? If so, what would your deco/stage setup look like? Would you stage a couple 80s of backgas and carry a couple 40s for your deco mixes? Or another 80 of 50/50? I haven't worked up the gas plan, but we are doing some deep (150'-200') dives this season and we are wrestling with this same type of question.

What do you recommend?

 

[Uncle Pug]

Did you and SG take Tech 1 and Tech 2 already???

 

[O-ring]

Uncle Pug once bubbled...
Did you and SG take Tech 1 and Tech 2 already???

SG isn't doing these dives with us, and we are in the training process at the moment.

 

[Uncle Pug]

Which class?

 

[MHK]

O-ring once bubbled...
Would you dive double 80s on the doria? If so, what would your deco/stage setup look like? Would you stage a couple 80s of backgas and carry a couple 40s for your deco mixes? Or another 80 of 50/50? I haven't worked up the gas plan, but we are doing some 200' dives this season and we are wrestling with this same type of question.

What do you recommend?

I probably would not use 80's on the Doria. A few factors would go into the decision. Number 1, the dive site is a 100 miles off shore, it's a very expensive trip, no boat that I know provides for Helium on the trip so you need to pre-blend and then top off, the weather is very unpredicatable, the water temp warrants a dry suit, and after going through all the hassle of getting there I wouldn't want to limit my BT's at all.. The way we did it last time was to use an AL 80 for the dive with a 16/50 mix, then we used AL 80's for deco. One with 50/50 and the other with 02. One AL 80 would last two dives. You must bear in mind that space limitation on the boat is a major, major concern.. I then had a 10/70 in my 104's back gas. The idea being that I used an AL 80 for the dive, had full back gas as reserve and if I ever needed to go to back gas I could just top off when I got back on the boat. If you get three perfect days of weather, you can actually get in 5 dives using the above method and you'll have proper mixes, sufficient redundancy and you'll accomodate deck space which is a problem on these very expensive trips.. AL 80's simply don't provide enough volume to use as your primary source for back gas. I guess if you wanted to just do a touch me dive, maybe.. The top is at 180, but it's a lot of work and money to get out there, so I want 25 - 35 minute BT's not touch me dives..

Hope that helps

 

[WreckWriter]

The way we did it last time was to use an AL 80 for the dive with a 16/50 mix...

So you're wearing 3 aluminum 80s and double 104s on your back throughout each dive? That seems an awful lot of bottles for a 200' dive.

I'm not a very big guy, I seriously doubt that I could stand up with that load. Could probably swim it but I don't know how effectively. I simply don't have training or experience carrying multiple stage rigged 80s.

How do you rig the bottles for this? Surely not a standard stage rig? Doesn't seem there would be room on one's left side for 3 80s. I've seen one 80 and 2 40s slung and that appeared a major PITA.

Personally for this dive I would try to bring 2 sets of 104s mixed rich (topping off to get 2, possibly 3 dives off each with 30 min BT), and 2 each of 50% and 100% in 40s along with an 80 of 100% for deco bottle top-offs. This would, of course, depend on the boat letting me bring all that but I don't think it would take up any more space than what you had (at least not much).

Do you feel that my method would not be adaquate and/or safe?

Thanks for your time, I really hope you'll answer.

WW