How to move double tanks around easily and safely---DIR needs to address this!

[Rainer]

Doing "recreational" dives in 80-100' doesn't necessitate doubles, GUE or other. Period. If you want to dive them (for whatever reason) go for it. Personally, I think they're overkill for many MDL non-overhead dives in this depth range.

 

[LiteHedded]

Doing "recreational" dives in 80-100' doesn't necessitate doubles, GUE or other. Period. If you want to dive them (for whatever reason) go for it. Personally, I think they're overkill for many MDL non-overhead dives in this depth range.

totally agree.

 

[lamont]

Since GUE instructors are now telling everyone ( which includes recreational divers) that if they are doing 80 or 100 foot deep nitrox dives, they need doubles---there is a danger that some will LISTEN and end up getting doubles

uhhh... what happened to diving single 130s to 100 feet and sticking close to your buddy?

a few years ago the argument against pony bottles was simply that your buddy was your pony bottle, and you needed to stick together, hence team diving...

worked great for me when i first learned that way...

 

[danvolker]

uhhh... what happened to diving single 130s to 100 feet and sticking close to your buddy?

a few years ago the argument against pony bottles was simply that your buddy was your pony bottle, and you needed to stick together, hence team diving...

worked great for me when i first learned that way...

Believe me, it's not my way...I think DIR for a nitrox dive to 100 feet is an hp 100 and a good DIR buddy....And I will not be using a set of doubles for this kind of dive, ever.
Then again, my buddies are all very good divers, and we all have very low SAC rates.

I think this is a direction that is being pushed to the hoovering masses....ask Bob Sherwood his take on at what depth, and what diver, for doubles..

One thing I do agree with the GUE position on...the aluminum 80 was fine fore doing 100 foot dives prior to nitrox--back when everyone dove air...But now with the durations desired by most for the 80 and 100 foot nitrox dives, an al 80 is just a very bad choice...



With good sac rate and good buddy, the hp 100 should be fine...with a poor buddy and mediocre sac rates, maybe the 130 size or the doubles are called for.

 

[Hepcat62]

I'm not sure that I agree that GUE is "pushing" doubles on recreational divers (at least not across the board). I think that the gas planning strategies they teach, when applied with actual measured RMV values, tend to discourage long SQUARE profiles at those depths on single tanks for divers with average (or worse) consumption rates. I think if anything, the GUE minimum-gas approach encourages being aware of how gas consumption works in the real world and diving multi-level profiles for people who want to extend dive times, which is of course exactly what the industry tells recreational divers to buy computers for. We're just coming at it from the opposite direction. GUE promotes planning, conservatism, and emergency readiness, rather than simply trying to sell getting as close to the NDL as possible, consumption rate be damned (or buy an air integrated computer).

Anyway... This is my experience here on the west coast. It may be different from some other locations, in that we have LOTS of shore and pinnacle diving at the recreational level that's 100% amenable to planning really nice multi-level dives.

 

[Ragnar]

I dunno, when my back feels a bit weak for some reason instead of lifting them off the ground I throw a backplate on them, get in sitting on my arse, lean forward and get up. Probably I should always do this, it works well. Same for getting out, kneel down, get one edge on the ground, put them down and get out. But yeah, tailgates and picnic tables are always welcome!

 

[TSandM]

Dan, I don't think this is a GUE thing. I think it's a Florida thing.

Errol posted a long and very eloquent plea for double tanks not long after our trip out there. I wrote to him about it, because I thought it was overkill. His answer was clear: Where HE dives, the dives are deep, and the rental tanks available are Al80s. Rock bottom on an AL80 for a 90 foot dive means you get a very short dive. Since larger tanks aren't an option, doubles are the only other answer. Even if big steels were available, you run into the "heavy tank with no redundant buoyancy" issue.

Where WE dive, you need so much ballast that a tank which is 2 or 3 pounds negative when empty is absolutely DELIGHTFUL. HP100s and HP130s are very common tanks for divers in Puget Sound, so people just don't need to move to doubles early, or often at all. Even our deepest and longest dives (remember, we're thermally limited ) can be safely done on 130s -- you really have to get into staged deco before doubles are really necessary.

I have never heard a GUE instructors on the West Coast insisting on doubles. In fact, I had dinner last night with one of the Monterey instructors, and he was expressing his frustration with the apparent "culture" of doubles that has grown up there, moving divers into those setups before their platform is really stable, and well before they need either the redundancy or the gas.

It's your particular environment -- it's not a global GUE thing.

 

[Scott L]

So long as one is wearing at least a 3mm wetsuit I cannot see where utilizing a 100HP cylinder would cause a diver to be over-weighted. Faber is -1lbs, Worthington -2lbs.

 

[Scarborough Diver]

I have a small collapsible cart that I use to carry my doubles from my car to the dive site. To pick the doubles up, I will grasp them by the shoulder straps of my harness and lift in a similar motion as a deadlift. If it will be an awekward lift (i.e. getting tanks into my dive buddie's van where he is afraid of scratching the plastic lip of the hatch) I will ask for someone to give me a hand and we will both carry them with one hand on the harness, other on the bottom of the tanks. If my harness is not on the tanks, I will use the bear hug method that was stated before.

I don't think that GUE pushes the use of doubles. Fundies can be done in single tank and it is perfectly acceptable. What I like about doubles is the redundancy. If I get a freeflow, I don't have to shove the corner of the mouthpiece in my mouth and hope for the best while I'm hemorrhaging my precious gas. I can calmly shut down, go to my other reg, and abort the dive safely. The argument of who should carry doubles and why boils down to...do they know how to lift properly? are they in good physical condition? do they have good balance while walking with doubles (learn by doing in a controlled environment)

I have been a competitive powerlifter for several years and have found that a lot of the training techniques that we use are applicable to lifting heavy dive gear. Simply put, lifting is lifting no matter what you lift. Exercies such as deadlifts, squats, romanian (straight leg with knees NEVER locked out) deadlifts, good mornings, bent rows etc... are all great exercises for strengthening the quads, hamstrings, glutes, erector spinae, and other muscles of the back to accomodate heavy lifting.

 

[Rainer]

What I like about doubles is the redundancy.

My only issue with this particular statement (and I think your other comments on lifting are all spot on) is that for many newer divers, and especially those who have yet to take C1 or T1 (yes, this includes those with a Fundies tech pass), doubles do NOT offer much, if any, redundancy. Fundies simply does not cover failures. All it teaches (at the tech level) is how to do a valve drill. If you've ever seen the first two days of a T1 class, you'll immediately recognize that there's a country mile between doing a valve drill and team diagnosing and solving a real failure.

IMO, many divers grossly over-estimate their capacity to deal with failures on the basis of simply owning doubles (or learning about valve drills). All that adding doubles does is *increase* the number of failure points on your back. It's only once you *and* your team learn to manage that hardware (C1/T1) that you gain actual redundancy.