Tips on starting diving doubles

[jborg]

periodically switching regs is likely good practice for emergencies anyway

It's not particularly great for donating to an OOA buddy as you'll randomly be breathing from either your primary or secondary and need to figure out what to donate, and the thing to donate may be clipped off or need some sort of breakaway, etc.

 

[SelfDiver]

It's not particularly great for donating to an OOA buddy as you'll randomly be breathing from either your primary or secondary and need to figure out what to donate, and the thing to donate may be clipped off or need some sort of breakaway, etc.

Or just donate whatever is in your mouth right now and sort out the "correct" regulator later?
Or do as the sidemount diver do but with the tanks on the back?

 

[rjack321]

Or just donate whatever is in your mouth right now and sort out the "correct" regulator later?
Or do as the sidemount diver do but with the tanks on the back?

Just go sidemount in the first place. Although it's also more complicated than need be for most open water dives, especially off a boat.

 

[SouthernSharktoothDiver]

@rjack321 why is sidemount better than independent doubles? Specifically assuming I can lift independent doubles fine and understanding there’s many weeds/logs/other impediments in the area, plus I like having my chest/sides clear

 

[rjack321]

@rjack321 why is sidemount better than independent doubles? Specifically assuming I can lift independent doubles fine and understanding there’s many weeds/logs/other impediments in the area, plus I like having my chest/sides clear

You can see the valves, gauges, leaks, and issues and can remove entanglements. Although getting them setup right is often much hard for beginners and it's not called "widemount" for nothing.

Your chest should not be encumbered in SM.

 

[grantmac]

If you offer me IDs or SM, I'll take SM everytime. Especially off a small boat, traveling or shore diving. Only place I'd want BM is wreck diving with big penetrations off a large boat and even then....

I've used (and dove) some very sub-optimal military equipment. I wouldn't take their using ANYTHING as a best practice.

 

[rjack321]

I've used (and dove) some very sub-optimal military equipment. I wouldn't take their using ANYTHING as a best practice.

No kidding. Navy stuff is usually a "best practice".... from about 1975.

 

[grantmac]

No kidding. Navy stuff is usually a "best practice".... from about 1975.

Hey at least I got to learn to dive using tables and a bottom timer?! While in a drysuit with non-isolated AL80s, yoke reg and FFM

 

[SelfDiver]

Hey at least I got to learn to dive using tables and a bottom timer?! While in a drysuit with non-isolated AL80s, yoke reg and FFM

Some of yall discussion on redundant computers shows a lack of dive planning capabilities.
People hating on yoke like every dive they do is 4,000 ft back in a cave.
Making steel tanks into villains.
Diving dry in Caribbean waters while finger wagging wetsuits.
Meanwhile, people breaking records with a tire inner tube BCD and DIY rebreathers.

 

[Nick_Radov]

@Nick_Radov Why do you say independent doubles are "convoluted junk?" Because I'm been mulling it over and thinking about them, and while I'm not sure they're the best course (still making up my mind on that), they do offer several advantages over a manifold. Ignoring the full redundancy (as many have said, an isolation manifold is reliable enough that I'm not so worried about it failing), you get a few things I like.

There's really no point in getting into the minutiae of exactly why independent doubles are convoluted junk. I'm sure your question was well intentioned but it fits a pattern that we've seen on online diving forums going back 30 years, since before this site even existed. It always goes something like this:

Hey guys, I've decided to do something wrong because (check all that apply):​

• I don't want to spend any money.
• I'm not willing to seek out high-quality training.
• No one else is willing to dive with me.
• I believed some nonsense I heard from another diver or "instructor".
• I haven't bothered to read through the archives but I still think I've figured out a better approach.
• I think my requirements are unique.

Now please help me work around the problems that I've created for myself by being unclear on the basics.​

​

And then we churn for pages and pages of verbose nonsense rehashing the same tired old points, with most of the posts full of pretzel logic from divers who have only half a clue themselves.

First, I have a rig that easy to put up and take down. So, rather than needing a designated set of tanks that are manifolded together (and have to be drained/need new valves to use as singles) I have a pair of tanks that I can turn from doubles to singles simply by removing two sets of bands (<10 minutes of effort, no need to go get new fills). Allows me to run multiple sets of doubles in a day without needing to bring them in as a unit (so I can bring a half dozen individual tanks and pair them off when I'm about to use them, easier to move and store in transit), and cuts down on me having more tanks than I need (which, even ignoring money as a consideration, because I could certainly afford more tanks, I only have so much space to store them). I hear people on here talking about having many sets of manifolded doubles, for different gas mixes and so on, and while I would love to be in a place to able to do that, I can't keep three sets of doubles and eight single tanks in my closet, but I can keep eight single tanks and two sets of bands much more easily.

Rent a storage unit or keep some tanks at the local dive shop when you're not using them or borrow extras from friends when needed.

Secondly, it's a setup I can travel with fairly easily. Much as sidemount divers commonly tout the benefit of being able to use any AL 80 at any destination, I can do the same just by packing a set of al 80 bands in my carry on and renting the tanks at destination. While I might could rent manifolded doubles, or pack in the manifold and valves as well as the bands, both of those are considerably more limiting. I don't currently travel to dive, but this is definitely a consideration.

You've got it. Just pack the manifold with you. Not a problem. Although if you're traveling to a dive destination so austere that you can't even rent a set of doubles with a proper isolation manifold then is it worth the effort? Maybe just stick to dives that you can do safely on a single tank and enjoy the vacation. When in Rome...

Now, on the flipside, you do get several advantages versus independent doubles. Draining the gas uniformly removes the need to switch regs periodically, but frankly periodically switching regs is likely good practice for emergencies anyway, builds muscle memory so that if your reg fails for some reason, you can smoothly swap to the other because you've done it a thousand times before. Similarly, a manifold does offer you all the gas in both tanks in failure, whereas independent doubles you'd lose one tank if it failed, but I'm diving neither cave nor deco. I don't have any kind of overhead, and my TTS is usually under 30 seconds, as I'm often in shallow enough water to need even so much as a safety stop.

If you try hard enough you can always find plausible sounding reasons to justify what you want to do. On the other hand, if you switch your mindset and decide to do it right from the beginning without compromising then the optimal approach becomes super clear and obvious. I'm not trying to be a jerk here but honestly you could get all of these issues addressed in a single day course with a competent instructor. Don't take the pontificating you see here too seriously.