Steel bands cover manuf. and VIP stickers

[ACR]

At the risk of putting words into his mouth, I think Sparticle is just encouraging that you get squared away with the basics first. That might happen at dive 10, dive 100, or dive 1000. (Or dive 2, dive 4, or dive 8- if you are down with base 2)

Now that's something I can agree with. I'm sure there are folks out there on dive 1100100 that don't have the basics down as well as a 'new' diver just finishing dive 11110... (base 2 just for you do it easy)

I think it's a great idea to have a mentor in this sport for exactly that reason

 

[wedivebc]

Actually before you do any/all of that, I would forget about doubles for now. You have <50 dives -- seriously, go get some more experience before you think about doubles. There's a LOT you can see on a single LP85.

Is diving doubles some rite of passage that only the diving elite can acheive? C'mon this is just typical of the dumbing down of the dive industry. If someone wants to dive doubles why should they have to relearn all the trim and bouyancy issues all over again when they switch.
There are people here who feel you need a special cert card or specialty training to do just about anything. Give us a break!

 

[DA Aquamaster]

Personally, I don't see a problem with starting a new diver off in doubles - I am pretty sure the US Navy still does it that way.

Way back in the day, the steel 72 was regarded as ideal for rec diving as it was thought to be impossible (or at least very hard) for a diver to get bent on a single tank - and with US navy table limits that was true for the most part until you got below 80-90 ft. The idea at the time was that divers used J-valves, no spg's, a depth guage in some cases and possibly but not neccesarily a watch or dive timer. So limiting tank size was sort of a primitive deco plan for the under equipped.

From that perspective doubles obviously caused concern in that the gas they carried had the potential to get you seriosuly bent at normal recreational diving depths in the 60 ft range. Consequently, doubles required things like a depth gauge, dive timer/watch and dive tables and enough knowledge and judgment not to do something terminally stupid with them.

None the less, in the era of single outlet manifolded doubles it was much more common for an average recreational diver to dive doubles and make either a long no deco dive or spread the gas out over two no deco dives and no one thought much of it as long as the diver was properly equipped to monitor time and depth and knew the NDL's.

Now however, in the era of dual outlet isolated doubles, using doubles is treated like some mysterious right of passage and where the level of skill require is well beyond the ability of a new diver. Of couse at the same time, you will also find at least a couple threads on the same boards where doubles divers are saying doubles are more stable than a single tank - and the two views are obviously conflicting.

The reality is that:

1. Doubles are heavy out of the water so a minimum amount of strenght is required - but you don't have to be superman as a little planning and technique go a long way toward reducing the strenght required to a lot less than you'd think.
2. Doubles have more gas than the average AL 80 so the bouyancy change from full to empty is greater - how much greater depends on the size of the doubles.
3. The "risk" is not greater just because you have two tanks. A single 130 has the same capacity and the same swing weight as twin 72's so it is hard to argue that tanks in the 72-77 cu ft range are more dangerous from either a swing weight or total gas supply perspective than a large single tank. Any of the above will get you equally bent or get you in similar trouble if you get stupid.
4. Pproper weighting is more critical in doubles as the swing weight is greater - but it is no harder to be properly weighted in doubles than in a single.
5. When paired with a well designed backplate and wing, doubles are extremely stable.
6. When paired with the average recreational BC, doubles are not as stable as a AL 80 sized single tank.
7. Way too many technical diving students get their first exposure to doubles in a tech class such as deco procedures, advanced nitrox, cavern, or intro to cave and spend the time task loaded with a brand new configuration with the result that they are less comfortable and have fewer resources to devote to the class. They would have learned more and progressed faster if they had been introduced to doubles much sooner in recreational diving situations that they had already mastered. It gets even worse when they are not properly weighted or trimmed in the new configuration during the class.
8. The best way to get started with doubles is to find a diver who dives doubles and see if they will help you get started in them.

Personally, I started with doubles years before I started any formal tech classes and the ability to go into a tech class with proper weighting, trim and configuration and have a large amount of experience with that configuration never failed to give me a great deal of confidence, reduce stress and allow me to focus much more on the contents and skills required in the course.

I think the current trend toward discouraging divers from using doubles until they reach X level of training, does them a diservice. It makes the process of transitioning harder and does help perpetuate the doubles mystique, but the idea that limiting the use of doubles or the gas they carry will keep divers safer is fatally flawed as poor judgment is poor judgment and that has nothing to do with a single or double tank.

 

[james croft]

As my dive buddy say: if one tank is good, two is twice as good.

Doubles can get you in trouble , but as long as you are aware of what you are doing I say go for it. DA Aquamaster nailed it in his post above. I think it is never to early to try stuff like this. Kinda like learning to drive a stickshift. Just do it so you don't look like a dork later in life.

 

[dschonbrun]

If you haven't received instruction on doubles, manifolds, isolation, and redundancy... you should really start there. Please do your first few doubles dives with an instructor. As well, if you are entering overhead diving territory, then take a course on Decompression diving.

Clearly we are excited for you, it's great to see people trying new things in diving. We all just want to make sure you have a safe and fun time.

 

[wedivebc]

If you haven't received instruction on doubles, manifolds, isolation, and redundancy... you should really start there.

Is there a course for that?

 

[micklock]

My 19th dive was in my new drysuit, my 27th dive was with my new doubles and then I dove the Straits of Mackinac my 42nd dive. I'm not recommending this to anyone but for me it was no problem.

 

[crpntr133]

Is there a course for that?

Some intro to tech classes teach this.

 

[DA Aquamaster]

Given the usual excessive charge to disassemble and reassemble doubles for visual inspections mine tend to get sent in as singles with K valves installed. I also ask them to put the VIP sticker exactly where the old one was and now and then some shops actually get it right. When they do not, it is usually not real hard to get the newly applied sticker off in one piece and stick back on in the right location. It just takes some care to work up a corner and then pull it up slowly and evenly across the rest of the sticker.

Most stickers I see today are a single layer plastic sticker that will peel off in one piece. A decade ago, metalized or multi-layered stickers were common and by design, they never came off in one piece.

 

[SparticleBrane]

I was sifting through some other threads regarding diving doubles and came across this comment that you made on December 9, 2007:

"My first dive in doubles was dive 40, with a set of LP95s. Didn't really have any issues -- I found them to be quite stable."

Not at all trying to call anybody out, but I'm just curious why the change of heart? In other words, do you regret that you started to dive doubles at dive 40 and, if so, why?

I knew this would come up. What I can honestly say is this:

• I came from a university dive program where buoyancy and trim were pounded into our heads from day one. I had multiple semesters of dive classes before I went to doubles and my skillset at that point was perfectly acceptable for their use. My first dive in doubles was, other than the first descent (where I learned quite quickly I had to hold the inflator much longer than on a single ), essentially like any dive I've ever done on a single tank. I didn't have any issues with buoyancy, trim, turtling, etc.
  
  
• I didn't own that particular set, so after a few weekends of using them, I went back to using my singles until I could afford my own set of doubles. It was really just something fun to do in the quarry during the summer, just a toy to try out. I didn't have any particular reason for using them -- I didn't need them for long dives, deep dives, cave dives, tech dives, etc (come'on, I had 40 dives! :14. They were just to go mess around in the quarry.
  
  
• I don't regret that I "started" diving doubles at dive 40, but like I said, note that I reverted back to using my singles for a good while until I could afford my own doubles setup. I also don't regret that I started diving them so soon, because I had the skills at the time that afforded me the comfort to do so. Going from my singles setup to using my friend's doubles was really a non-issue. They were a bit heavier on land, more mass to push through the water, and slightly more stable. That was really almost all the noticeable differences.
  Don't take that as saying I never had any issues. A month or two later I was diving that set of LP95s and for whatever reason I was doing headstands on that dive. If I recall I was using the same wing but on different mounting holes. I believe there was also a slow leak of the auto-inflator...:blinking: Everyone has bad days sometime, hey?
  There is always a learning curve with new equipment and doubles aren't any different, but it can be much shorter and easier if the diver has higher quality basic skills from the get-go.

At the risk of putting words into his mouth, I think Sparticle is just encouraging that you get squared away with the basics first. That might happen at dive 10, dive 100, or dive 1000.

Your mentor should be able to give you some guidance.

do it easy, that's exactly what I'm saying. Which leads me to my next point...

7. Way too many technical diving students get their first exposure to doubles in a tech class such as deco procedures, advanced nitrox, cavern, or intro to cave and spend the time task loaded with a brand new configuration with the result that they are less comfortable and have fewer resources to devote to the class. <...snip...>
8. The best way to get started with doubles is to find a diver who dives doubles and see if they will help you get started in them.

I really think that the first part of #7 and all of #8 should be combined, with a caveat. Yes, WAY too many students do their first doubles dives in classes. This really shouldn't happen -- students should use in class what they're comfortable with. If a students knows doubles are required for a certain class, they should get comfortable with the setup before the class, which is where #8 comes in. Get in touch with someone who is familiar with the setup and have them walk you through it. They're not rocket science, but having someone familiar help you out is always good. Just make sure they know what they're doing in the water too...if they strap on some doubles and walk around on the bottom, avoid them like the plague.

They would have learned more and progressed faster if they had been introduced to doubles much sooner in recreational diving situations that they had already mastered. It gets even worse when they are not properly weighted or trimmed in the new configuration during the class.

DA, I really think that going to doubles should almost be a non-issue. The diver should be able to strap them on the first time and not have problems -- this comes from a strong foundational basis. If the divers don't have their basic skills up to par, doubles will be a pain. Of course there's always a learning curve (as their is with any change of gear configuration), but serious problems like what you were discussing earlier can be avoided entirely if divers has higher quality basic skills before progressing further to doubles.

I think the current trend toward discouraging divers from using doubles until they reach X level of training, does them a diservice. It makes the process of transitioning harder and does help perpetuate the doubles mystique, but the idea that limiting the use of doubles or the gas they carry will keep divers safer is fatally flawed as poor judgment is poor judgment and that has nothing to do with a single or double tank.

DA, I agree with you 99% of the time but I'll disagree with you here.
Most divers I've seen who switch to doubles don't do it because they need them for a particular type of diving. Rather, they switch because everyone else around them is diving doubles, and they don't want to be the only one in a single tank setup. Peer pressure is a big motivator..."All the cool kids dive doubles!"

Is diving doubles some rite of passage that only the diving elite can acheive? C'mon this is just typical of the dumbing down of the dive industry.

On the contrary...
Diving doubles should really be viewed more as a tool than a "rite of passage" (speaking of which, that is not how I view it. ) If the diving you want to do requires the added gas and redundancy that is offered by a doubles setup, by all means -- go do it. Otherwise, what's the point?
This is not the "typical dumbing down of the dive industry". If you note in my post, I'm advocating raising the standards -- have good basic skills before going to doubles.

If someone wants to dive doubles why should they have to relearn all the trim and bouyancy issues all over again when they switch.

They shouldn't, that's my point. I've said it a million times in this post -- if a diver has good basic skills before switching to doubles, the switch is a non-issue. They don't have to "relearn" anything. The concepts of trim and buoyancy are the same in doubles and singles. With good basic skills, the learning curve is usually less than 3-5 dives until the diver is just as good and proficient in doubles as singles. Without a solid foundation...many divers never figure it out...