Doubles etc.

[TekDiveGirl]

My advice if you can't find any good technical divers in your area to start hanging around and start learning from --- and even possibly starting to take you under your wing, then find a qualfied instructor in yur area and take some classes.

Getting yourself into doubles means longer bottom times--- a total change in gear configuration --- a change in emergency procedures --- and without proper training or instruction could be a recipe for disaster.

 

[Adobo]

Simply taking more air with you might cause more problems (and even lead to your death) then it solves.
and before you take on doubles etc. get certified in deco procedures, it will save your life.

What? More gas might lead to your death?

 

[NJScubaDoc]

find out what your SAC rate is and if it is excessively high

most of the diving I do is in cooler water. While my drysuit and underwear do a lot to insulate me, cold body temperature is going to require increased aerobic cellular activity to keep homeostatic temperatures at 98.6, which will translate into more gas for my cells.

if I was in warm water, taking my time and only taking pictures I'd be able to easily get incredibly close to my NDLs (which is what happens when I'm on vacation in the tropics) at home however, I'm usually spearfishing, lobstering, or chasing something.

You are absolutely correct though, I wouldn't think of getting into deco procedures without the proper training.


Thanks for the thoughts.

 

[plwtwo]

Another point, What about your buddy?
Do you dive with the same buddy(ies) often?
Are you diving with insta-buddies?

If you're diving with the same people, are they going to go with double as well?
If you're doing a lot of insta-buddy diving it won't matter if you have doubles...

Just something else to consider. IMO, you should try and work on your SAC rate now, if possible...I'm a big guy who, likes air, lots of it, but I still can't benefit from doubles because all my dive buddies are using singles..

 

[Data]

What? More gas might lead to your death?

more gas for the untrained recreational diver means he/she can easily exceed NDL without realizing it.
if at that point something happens to the equipment or whatever and the diver makes an emergency ascent or simply doesn't know he/she is in deco and ascents, he/she will get the bents, which have let to death before.

 

[jeckyll]

NJScubaDoc:

I recently went through a similar change. Two things drove my change to doubles:
1) For some of the best local wrecks I needed to be able to spend more time at 100 fsw and I was running into barriers due to Rock Bottom vs. NDL.
2) I wanted to take Fundies and I wanted to do it in doubles.

IMO, diving doubles isn't that big of a change if you are used to diving a long hose and BP/W. I had 10 or 12 dives pre-fundies and it worked out great. Now, I did make sure that those dives were of a sandy bottom, starting very shallow and progressing slowly from there.

My regular diving buddy switched back to diving doubles when I switched to mine, it is certainly nice to have someone you dive with configured the same way you are. But there is certainly going to be a fair bit of expense and a bit of an increase in complexity (i.e. valve drills).

I would recommend taking an intro to tech / Fundamentals etc type class. It did teach me that I am probably another year and probably another 100 dives minimum away from getting into deco diving, if at all.

Best of luck

Bjorn

 

[jeckyll]

more gas for the untrained recreational diver means he/she can easily exceed NDL without realizing it.
if at that point something happens to the equipment or whatever and the diver makes an emergency ascent or simply doesn't know he/she is in deco and ascents, he/she will get the bents, which have let to death before.

Good lord. I can easily exceed my NDL using an AL80 on air at 100 fsw too.

Getting doubles doesn't change that.

Getting a pony doesn't change it.

Getting your skills dialed in and you awareness to where it needs to be, that changes everything.

 

[Adobo]

more gas for the untrained recreational diver means he/she can easily exceed NDL without realizing it.
if at that point something happens to the equipment or whatever and the diver makes an emergency ascent or simply doesn't know he/she is in deco and ascents, he/she will get the bents, which have let to death before.

Recreational divers can also very easily exceed NDLs through repetitive diving, no?

 

[nereas]

first off, don't listen to something like this.
diving a balanced rig has nothing to do with how many tanks you use. let's just stay with that and not go any deeper into it.

I think NJScubaDoc is taking this approach from the wrong side.
once you go into doubles, there is a lot more to it then only giving you more gas.
maybe you should work on extending your bottom time with what you have.
let's do a little SCUBA math.
depending on what gas you use and which tables, let's just say you have a NDL of 30min at 100'
if your setup is dragging, your weighted wrong and your trim and buoyancy is crap, you might have a SAC rate of 1.0.
this means at 100' (4ATA) you suck through 4cf of gas per min.
to get to your NDL you would need 120cf of gas.
now you change your setup, you become perfectly balanced, your trim and buoyancy is spot on and you dive a lot more.
your SAC rate is now 0.5 and all of a sudden you only need 60cf for the same dive (easily done on a AL80).
first things first, check your dive profiles, find out what your SAC rate is and if it is excessively high, find out why, talk to experienced divers and ask what changes should be made on your current setup and see how it goes.
only when you're sure you have done everything possible to get the best out of what you have, look into taking a different route in your diving adventures.
simply taking more air with you might cause more problems (and even lead to your death) then it solves.
and before you take on doubles etc. get certified in deco procedures, it will save your life.
just my 200psi

First off, don't listen to something like this.

Anyone who calls himself a "divemaster" and is unaware of the stigma that naturally goes with such a title is not likely to know how to match a person and their SCR with properly sized tank(s).

Determine on your own, or by speaking with instructors, what single tank size best fits you and your diving.

 

[NJScubaDoc]

Another point, What about your buddy?
Do you dive with the same buddy(ies) often?
Are you diving with insta-buddies?

Most of the time I'm not diving with a buddy. I wouldn't exactly call it solo diving, but I do not wish this to become a discussion of solo diving.

I would not apply this practice to decompression diving though. If I were to venture into deco diving I'd do with with a dedicated buddy.

I would apply it to carrying doubles and diving within NDLs. At the moment I'm considering using cam bands to double the 95s together and diving them as independent. I like the versatility of this, and the task loading isn't a problem.