Doubles for Recreational Diving?

[jackass]

I am wondering how many of you use doubles for recreational diving? I realize that recreational is a vague word. So when diving in open water, max depth 140 feet, no plans for decompression.

If you do dive doubles recreationally: why? when? and how do you plan multiple dives?

Thanks for any responses.

 

[Ber Rabbit]

I've just started using doubles and intend to use them recreationally. I prefer to dive in the 40-80 foot range with them. I have an aversion to changing tanks between dives, don't know why but it's something that I've always disliked. I can do a whole days worth of dives at 40 feet in double 100's then get them filled overnight and start over. Packing the extra weight is worth it to me to avoid changing tanks, strange but true. Planning is the same as with several single tanks and I can snack while my buddies swap tanks
Ber :lilbunny:

 

[Jimmer]

The only time I'm ever in a single tank is in a pool or on vacation. I prefer the redundancy of havign 2 regulators, espcially for cold water, I prefer the stability of doubles over a single tank, and like Ber said, no need to swap tanks between dives on a charter. Now that being said I own 3 sets of doubles, 108's (soon to be sold and replaced with 130's), 72, and 45's so I always have a nice size of doubles without needing to lug around my big suckers.

 

[Walter]

If you do dive doubles recreationally: why?

Originally because I needed more air for deco wreck penetration dives (Outside your definition, but I was diving for fun, so they were recreational dives), but later I started using them for most of my diving because they are easier than single tanks. Twins are more evenly balanced side to side than a single tank.

when?

Quite often, depends on what mix I might have in my doubles and the dives planned.

and how do you plan multiple dives?

Same as I plan them when I'm diving singles, except I need to surface with enough gas for my second dive.

 

[Divin'Papaw]

I've just recently moved to doubles and I will be primarily diving them recreationally. I went to doubles for three reasons.

(1) Same as Ber, I hate to swap tanks out. I really like the idea of set it up once and I'm good for the day.

(2) You get more dives out of doubles than two singles. What?! Am I nuts?! I actually don't see folks talk about this aspect much. If I do a good, solid recreational dive in one of my HP100s, I have between 800-1400 PSI left. That's then too low to do another dive and have a conservative safety factor that is important to me. On the next dive, same thing ... 800-1400 PSI left. That's two tanks with 800-1400 PSI left. Time for fills. With doubles, thats equivalent to one tank with 1600-2800 PSI left. Now that's different. That's enough for a solid but shallow recreational dive. Therefore, I'm finding that I can get 3 good, solid recreational dives (even 4 if they're all shallow) on my double 100s where I'd only get two if they were singles.

(3) I'm beginning technical training this year. I don't think I'll ever be to the point where tech dives are the majority of the diving that I do, but I would like to expand my diving options by being trained to utilize decompression and EAN mixes higher than 40%, primarily for the wreck diving that I like to do.

 

[crlavoie]

I'm just starting with double 120's but it's for all of the reasons previously listed. I don't anticipate using my single rig very often.

 

[PerroneFord]

I am wondering how many of you use doubles for recreational diving? I realize that recreational is a vague word. So when diving in open water, max depth 140 feet, no plans for decompression.

If you do dive doubles recreationally: why? when? and how do you plan multiple dives?

Thanks for any responses.

I use doubles for recreational diving.


Why?

All my singles are in use for stage bottles or something else.


When?

Every dive.


How do I plan multiple dives?

First dive is done with an AL80 stage. Second dive is on doubles only. If I am not taking the stage bottle, then I dive thirds on the first dive, the recalculate thirds for the second dive and dive that.

 

[MSilvia]

why?

Redundancy, maximizing available gas and bottom time. That aside, it gives me an opportunity to stay proficient for dives I do outside of rec limits.

when?

When I'm diving deep, doing multiple boat dives, or when I want a shore dive to potentially last for several hours.

how do you plan multiple dives?

It depends on the dive, but generally speaking I'll plan to leave enough gas in reserve on the first dive(s) to ensure I can make the dives I'm planning later. I'll also make sure I always have enough gas to get to the surface while sharing with a buddy. Let me know if you need details on how to do those calculations.

 

[WD8CDH]

I hardly ever dive with my singles. I prefer multiple small diameter tanks for less bulk. My primary rig is triple 40s but I also dive with double 40s, triple 35s, triple 72s and quad 20s. Except for the double 40s all of my multiple tank rigs have one independant tank for a redundant air supply. All of the rigs can handle multiple regulators with independant shutoffs.

 

[astrofunk]

All my dives are recreational in the sense that you described. I dive doubles almost exclusively, for primarily the same reasons given by other folks. (I'll dive singles if I'm diving from my kayak, or if I'm making a rough shore entry that I feel requires some real agility.)

As for gas planning, since my buddies are generally diving singles, I find it easiest simply to pretend that I'm diving just one tank at a time. So if I'm diving twin 72s with 2400 PSI, say, I allot the first 1200 PSI to dive one and the second 1200 PSI to dive two, and I plan accordingly.

Of course, in the back of my mind I know that I have far more flexibility than that. And thinking along those lines I usually leverage the kind of advantages that Divin'Hoosier described. For instance, I often burn up ALL of dive one's allotted gas, since there's no need for saving 500 PSI in reserve, or diving rock bottoms -- whatever is you like to do -- if I still have an entire cylinder's worth of air left. And then on dive 2, it's exactly as if I were diving a single 72.