Diving with Twins

[TSandM]

Is training required? No. No one will stop you from buying a set of doubles, two more regulators, a backplate, a doubles wing, and strapping it all on. At least, nobody stopped ME.

Doubles aren't hard to dive; they're hard to drag around on land. But, unless you learn how a manifold works and how to manage the potential failures (how to reach and manipulate your valves, and how to work with your buddies when problems happen) you are much better off in a large single tank for a bigger gas supply. An HP130, well filled, holds almost as much gas as our double 72s do.

As has already been stated, if what you are worried about is that your dives are very short, relax and realize that this will improve with time. As you become more relaxed and more facile with the act of diving, your gas consumption will drop. There are things you can learn to accelerate this process (some listed HERE) but most people aren't going to need to go to doubles for an adequate recreational gas supply.

As for where to get them, your local technical diving shop would be happy to order you two tanks, bands and a manifold, and assemble them for you, for a fee. Or you can haunt any local tech diving forums you might have, and watch for people selling doubles. Many people get into technical or cave diving for a few years, and then let it go, and their loss can be your gain.

 

[ianr33]

I cannot believe an instructor encourage any form of diving without training.

I agree. The instructor will miss out on lots of $$$$ if he does that.

Some courses are essential (Cave) some are optional (drysuit) and some are just stupid (Boat Diver)

 

[NJDiver07866]

Wow.... came back to this to see how the OP made out and this took on a cyber drama life of it's own. All good advice from the above posters. As for the C-cards....

I will be honest, here in north east the local diving is dying out. You look on a boat and you will see old salty dogs and the younger folks get more entertainment out of other recreational activities. A few new faces show up and often get turned off real quick because of the financial stress it can cause.
OW total $600 (class, materials, equip, local check out etc..)
AOW $400 (ibid)

This is the minimum...to get these guys out on a boat figure another $85 ride on a boat, getting up at 3AM, Rental of gear $75, Gas/Tolls $25, Tip $20.

The stress of some people never being on a boat for long duration, getting sick, sunburn, finding a good mentor to hold your hand all adds stress.

As an instructor it's not my full time work, I do it because I love the sport. I have also felt like a sheep getting fleeced in this sport with money. This is why I strongly support mentor relationships and not c-card relationships. I remember being a new diver going to warm waters and getting on boats that I felt like cattle. I had no idea there was better diving out there. Luckly I ran into some people that showed me the true value of the sport and not the business side. Yes without one you can't have the other, but I see too many instructors doing this as a means of income and not for the love of the sport. Does it feel good to get a few hundred bucks? yes, does it take the sting out of the $20K+ I have paid into the sport? yes, but to ask for another $350 for a F*cking boat c-card is bull*hit. Pigs get fat hogs get slaughtered. This entire *intro to tech* cert?!?!?! You want me to charge a student $350 to put on a set of doubles??!!?!?! and doing some skills with them???

Everyone has their own montra, and way I respect that. For me I don't mind charging for my time/efforts. But if instructors are not seeding their students instead of harvesting them all the time you won't have any left. I bring them up the ranks, but if a student wants to try a set of doubles when they are under my wing I will get a liability release form from them and spend time with them. Business first to cover my @ss, seeding second and building a better diver and crops for tommorrow. You have to make it fun for these kids. If they walk into the sport and say 'hey I want to dive' don't say $400 for this, $200 for that.. say 'hey lets go play in the pool and see what you think'....

And yes every student may have a unique case, or they shopped leisure pro ( I have) you can't say oh get out of my shop, just be thankful they are asking about a set of doubles instead of thinking about what to charge them..

Again, every case is unique, a few students just want business. They don't care about the mentor relationship, they are well off with money and just want the business of c-cards. With these guys you trim a little meat of them to hold you over for the skinny young kids that don't have two dimes to knock together...


Dive safe all

 

[halocline]

Yes, training is required.

Really? I dive with doubles frequently and I don't have any training for it; guess I missed the memo.

There is a learning curve, but that's true for many things in life.

 

[Walter]

Once upon a time, I decided I wanted to take more air with me on a dive than was possible using one tank. Large tanks were still in the future. I thought twins would be a pretty good idea. I bought two matching tanks and a non-isolated manifold (I'm not sure isolated manifolds were available at the time). Using scrap aluminium, bolts, and clamps I put them together in a twin set. Next, I bolted them to my Scubapro stab jacket filled them and went diving.

What did I discover diving twins for the first time? They are easier than diving a single tank.

 

[Jim Lapenta]

I did indeed take an intro to tech course. Not to dive doubles since I already had a a set of 72's and had a number of dives in them, but because it was coupled with my Helitrox course. I am one of those instructors and there are more of us who think that students should come back for more training because they want to. Not because they have to. I train my OW students who want to dive locally and maybe warm water locations so that if that is what they want they will never have to come back. Especially for stupid stuff like boat diver, manatee diver, kitchen sink diver etc,.

An OW diver should have everything they need to continue to dive AND expand their diving with experience, some mentoring, and good judgment to most areas they are interested in. No reason an OW diver cannot dive to 100 feet if they have taken the time to get their buoyancy and trim down, learn their air consumption rates by GRADUALLY increasing the depths of their dives, understand the risks, choose good buddies, and continue to work on their dive skills.

AT the same time I offer an AOW course that gives them a leg up so to speak on the knowledge and skill portions. I don't do a "tour course" .They will learn a number of new skills and gain addtional knowledge based on my experience and training that will still require them to have gotten some dives in on their own. If they have not gotten comfortable with the basics I won;t even let then start any "advanced training".

There are other things where I do feel having a formal course helps as well. An UW Navigation course from someone who actually knows how to navigate makes life a lot easier. But again they have to have had more than an OW course that gives them just enough to be led around by a DM or Guide.

Finally I mentioned good judgment. This is a personal thing that is pretty much developed individually but when it comes to scuba the OW instructor can make or break a divers ability to do that. Go on as if it;s all fun and games and the diver is screwed. because it is a good bet that at some time they will choose to do a dive that scares the crap out of them or presents a problem that could get them hurt and in fact has. Even killed some. It always needs to be in the back of their mind to think before saying yes to an unfamiliar dive or situation. They need to understand that new dives and more complex dives do have greater risks. And sometimes the greatest dive planning involves saying no to the DM, Guide, Buddy, etc. I know of at least a few divers that would not be dead if they had done this. But their OW training gave them no reason to think to do it. And that sucks.

 

[captain]

No one asked him why. Does he just want more gas, does he want redundancy, does he want to do deco, does he just want to look cool. When we know why we can advise him better.
I sometimes dive doubles but to me doubles is 2 tanks on a single outlet manifold. I don't want or need 2 regulators. I like the balance of them.

 

[spectrum]

Does diving with twin tanks require training,

what do I have to do/get to use them.

:sblogo:

As many have queried, what sort of diving do you planed for them? If you seek to make obnoxiously long shallow shore dives then most of it can be figured out with a little research and perhaps some mentoring.

If the plan is to embark on dives that are beyond your training then get trained for those dives. This will encompass doubles configuration and use.

If you don't consider your self good at self study and asking questions then seek training. If it's not something technical you are getting into you may just need to work with an experienced doubles diver to cover the bases informally. Not all transference of knowledge results in an agency card.

Disclosure; I don't dive doubles but if I snag a set for my local use that is how I would approach it.

Pete

 

[kanonfodr]

Interesting thread as I did my first doubles dives today. I have no real training in doubles (but have done training where another diver was in doubles), and while I spent the dives doing the same thing every other diver does when diving (blowing bubbles, looking at cool stuff underwater, and having a good time) I made sure both before I did the dive and in the water I could reach all my valves. The rest is pretty basic stuff (proper trim, neutral bouyancy, effective propulsion).

That being said, doubles do dive differently than singles do (for me they are head heavy, got some work to do) but the stability is unrivaled in my single tank diving. At one point I flipped myself over onto my back and just floated in the water like I was in a recliner, it felt pretty nice. Oh yes, and they are much different on land. Or in the surf. I managed to make a great slide to home plate after being caught by a wave right above the ankles. Somewhere above a scuba diving umpire was blowing his whistle and yelling "Safe!"

But why do you wish to dive doubles? My reason is not only for the redundancy but also the increased gas supply and the fact that any unused gas from the first dive goes right into my second dive unlike single tank diving. That would be a boon to the normal boat dives here where the first is a deep dive that is limited by MDL and then a second shallow dive that is more likely limited by gas supply. I'd quite possibly drown the DMs in that case .

If you have the proper equipment, mindset, and you are confident in your ability to handle them both in the water and more importantly on land; go for it!

Peace,
Greg

 

[elan]

I cannot believe an instructor encourage any form of diving without training.

Where can I get my "Tank Banger Operator" C-card ?

To the OP. Definitely go for it. You can easily start diving them off the shelf with no special training. You can checkout some DIR resource that can give you an idea on how to route the regulators. If you do not take any training or mentor ship you will just get a bigger "single tank". Meet some people who know not to operate the manifold and show you how to do it than you will be capable of getting the best use out of them and make them actually work as doubles. For the first 15 dives I was actually diving them as a bigger single tank, just to get the feel of them.

Perfect the trim with them, balance them if necessary, that will keep you busy for 20 dives or so. Then you can start doing the manifold. Many people including myself and many of my buddies were very much concerned about reaching the valves while forgetting about the trim and balance, struggling a lot. But when the trim was kind of sorted out it became so much easier. AS always you have to watch your time not to overrun the NDL, this is not something doubles related but bigger tanks related issues. Some people are just tailored too much to the PSI tracking on AL80 or smaller tanks. So you should be care full. You can make 2-3 no deco dives on some of the double tanks, say 200 - 260 cuf sets.