Sling tank or doubles.

[DevonDiver]

Not sure whether this should be here or technical...
Just did my wreck course and are qualified to dive to 40m.

Definitely here.

At the moment I am using a standard BCD and tank, but am finding I am gas limited for the deeper dives.

The first thing to do is examine your SAC. Deep wreck diving is quite an advanced pursuit, so every dive should have a proper gas plan. Prior to getting into the water, you should have a clear understanding of your gas needs for the dive, your contingencies and your turn-points.

There is also the concern about not having redundant gas for entering a wreck.

That's quite a big concern, when diving deep in an overhead environment. The ability to donate/recieve gas from an attentive buddy is the core of the recreational diving system.

However, the effectiveness of the buddy system can often be compromised when deep/wreck diving. Restrictions inside a wreck can mean that air-sharing can become difficult, or even impossible, when exiting the wreck.

In addition, most recreational wreck divers don't recieve any training in the gas planning procedures needed to ensure that they have sufficient gas to share for exit and ascent (gas matching within turn-point calculation).

Proper gas redundancy, to allow unsupported exit and ascent from a wreck is a critical issue.

On the other hand I do a fair bit of shore diving, and in those cases I normally don't need the extra gas.

If you're going to be involved in specialist diving activities, it often involves an acceptance that one single configuration is no longer going to be ideal for all of your dives.

Advanced diving activities mean more expenditure on kit and training.

The first option would be to do a sling/stage tank. the advantage of this is that I could continue to use all of the existing equipment, with minimal changeover, but will meet the extra gas/redundant gas requirement. The disadvantage is that I would have to buy the doubles in the longer term, so it is only putting off costs.

Sling tanks are not ideal for wreck penetration. The obvious issues are entanglement and cross-section (getting through restricted areas).

With a single tank of back-gas, you'd need a sufficiently sized pony/stage to ensure you could exit the wreck and ascend. Unlike normal open-water diving, the fact that you could be deep within the wreck, in limited viz, possibly entangled etc... means that your contingency gas calculations would need appropriate padding.

Basically...it'd need to be a big stage cylinder.

the second option would be to go to the full doubles. The advantage is that this is needed in the long term (probably). The disadvantage is that some of my gear (yoke 1st stage) would be made redundant, and it would be harder to convert back to a normal set if I was doing a shallow dive....

This is why technical divers will always warn potential tech divers about the large cost involved.

If you're going to be penetrating wrecks in deep water, then you need the proper kit and training to do it. Any short-cuts in this are made at the expense of safety.

What would your suggestion be?

If you're serious about proceding into tech diving and you also intend to conduct deep wreck penetrations, then I'd say it's time to invest in the proper equipment.

Get a BP&W and doubles. Save your jacket BCD for the shore diving.

Using doubles isn't the 'preserve' of technical divers. They are a valid choice for any diving scenario that requires a considerable amount of contingency/redundant gas.

 

[evil_xander]

What Andy said - in the longer run much less expensive and more safe way then cutting corners. Take your time and enjoy diving.

 

[franny]

Definitely here.
The first thing to do is examine your SAC. Deep wreck diving is quite an advanced pursuit, so every dive should have a proper gas plan. Prior to getting into the water, you should have a clear understanding of your gas needs for the dive, your contingencies and your turn-points.

Thanks for that, always good to know I have put it in the right spot.

As I said, I think it is 0.6cf/min, but the plans to spend some time diving and doing that stuff got overridden by events of Friday night. I od know how to calculate the gas requirements from the courses I have done. I won't be both going deep (over 100') and penetrating on the same dive, as I know that I am not that good yet.

That's quite a big concern, when diving deep in an overhead environment. The ability to donate/recieve gas from an attentive buddy is the core of the recreational diving system.

However, the effectiveness of the buddy system can often be compromised when deep/wreck diving. Restrictions inside a wreck can mean that air-sharing can become difficult, or even impossible, when exiting the wreck.

In addition, most recreational wreck divers don't recieve any training in the gas planning procedures needed to ensure that they have sufficient gas to share for exit and ascent (gas matching within turn-point calculation).

Proper gas redundancy, to allow unsupported exit and ascent from a wreck is a critical issue.

Which is one of the reasons I am worried about having some extra gas for doing wreck dives. I know that sometime i may need to do an ascent without a buddy, and knowing that I have enough gas then becomes important.

If you're going to be involved in specialist diving activities, it often involves an acceptance that one single configuration is no longer going to be ideal for all of your dives.

Advanced diving activities mean more expenditure on kit and training.

I know I will have to spend the money, and that as I get more advanced it will get more expensive. A combination of SWMBO and ensuring I have buddies to push the point I am reaching means I don't want to overreach with the gear.

Sling tanks are not ideal for wreck penetration. The obvious issues are entanglement and cross-section (getting through restricted areas).

With a single tank of back-gas, you'd need a sufficiently sized pony/stage to ensure you could exit the wreck and ascend. Unlike normal open-water diving, the fact that you could be deep within the wreck, in limited viz, possibly entangled etc... means that your contingency gas calculations would need appropriate padding.

Basically...it'd need to be a big stage cylinder.

I understand that the sling is not perfect for wreck diving, but if I don't own my own, I know I will get pressure from the local operator if I penetrate the wrecks on their dives.

This is why technical divers will always warn potential tech divers about the large cost involved.

If you're going to be penetrating wrecks in deep water, then you need the proper kit and training to do it. Any short-cuts in this are made at the expense of safety

If you're serious about proceding into tech diving and you also intend to conduct deep wreck penetrations, then I'd say it's time to invest in the proper equipment.

Get a BP&W and doubles. Save your jacket BCD for the shore diving.

Using doubles isn't the 'preserve' of technical divers. They are a valid choice for any diving scenario that requires a considerable amount of contingency/redundant gas.

Fair call, and to an extent true. The plan is to eventually go down that path, but to justify 3 full size tanks at the moment (and all the sundries) is a big initial outlay. The plan was to stage that expense so it didn't hit quite so hard.

Thanks all for the information. You have given me a lot to think about.

 

[Colliam7]

The first option would be to do a sling/stage tank. … the second option would be to go to the full doubles.

Although I personally love diving doubles (double HP100s or double AL80s) for recreational wreck dives, I would recommend the first option. As you said, it allows you to defer / spread out the capital outlay. It sounds like you are serious enough about diving that your initial gear purchases should reflect your longer term plans, to dive deeper, and to dive wrecks. Anything can change, but it is appropriate to plan for that given what you have said.

My thoughts:

• First tank should be a larger tank (as TS&M mentioned), such as HP100, HP119, or HP130
• Second tank should be an AL 40 (they are ALWAYS useful, as a slung recreational pony, as a slung deco bottle, even as part of a two AL40 side mount rig, etc.)
• Third tank should be a twin of the first tank, which allows you to move to doubles, either back mount or side mount

The disadvantage is that some of my gear (yoke 1st stage) would be made redundant, and it would be harder to convert back to a normal set if I was doing a shallow dive

If the first stage you already have can be converted to a DIN configuration, do it. It can be used for singles, with a DIN to yoke adapter as necessary, or doubles, eventually (see comment, below, about regs).

it honestly becomes a pain in the rear swapping your regs between singles and doubles setups every weekend

Yes! Advancing your diving - in terms of depth, and venue (wrecks, caves, etc.), and skill set (and training) required – almost inevitably involves some acquisition of more gear. It doesn’t have to be a LOT of additional gear, but you will ultimately find it easiest to have gear sets already configured for special applications – single tank recreational, double tank recreational, double tank technical, sidemount – as finances allow.

Many divers who end up in back-mount doubles evolve through a series of tank options, as DaleC indicated. Many divers currently using sidemount moved to that point after going though backmount. My own tank and regulator configuration evolution: 1) DIN reg + DIN-yoke adapter; 2) AL80; 3) HP120; 4) HP120 + AL40 + second DIN reg; 5) Double HP120s + two new DIN regs configured for backmount doubles; 6) Double HP120s +AL80+AL40 + fifth DIN reg, for deco diving; (Floodgate opened, financial ruin ensued); 7) Double AL80s (x 2); 8) Double HP100s + second set of (4) DIN regs, as back-up regs for backmount deco diving; 9) Double HP 130s; 10) Sidemount HP100s + conversion of two back-up BM regs to SM configuration; 11) Sidemount AL80s + two more DIN regs configured for SM

You originally asked (only) about gear, and this response focuses (only) on gear. You have also received some very good advice on training, which I support as well.

 

[franny]

Colliam,

Thanks for the feedback.

Regs are about due for a service, so I will ask if it can be changed to DIN.

The tank ideas are greatly appreciated.

I have noted the comment on the training, and I plan to look at my options.

 

[AndyNZ]

Just did my wreck course and are qualified to dive to 40m. At the moment I am using a standard BCD and tank, but am finding I am gas limited for the deeper dives.

Apply Occam's Razor.... for any given problem with multiple solutions, the most simple solution is likely to be the best.

Your best option is simply to do shallower dives and don't buy anything yet.

Any debate involving doubles or slung tank will always be polarised, but there is no right answer. Ultimately, if you are looking to do deeper penetration dives then you will end up with both doubles and a stage tank. The knack is to minimise any upfront mistakes in buying gear that isn't quite right. You'll dick around trying to make it right because you spent the money and never quite enjoy the dives and end up begrudginly spending way more to get it right.

So, the two parts of the solution. Go and do a whole bunch of shallow dives. Reducing SAC rates comes from two things - comfort in the water and better fitness. If you have the option of doing a 10m dive for an hour then over time that will get more comfortable than doing a 30m dive for twenty minutes.

The second part, don't buy anything. Beg, borrow or steal different setups and try them for yourself and see what works. When you see someone with something a bit different, ask them why. Get them to explain the advantages. Absorb all the information you get and then decide what is right for you - once and only once, rather than buying stuff that ends up being relegated to the back of the broom cupboard.

 

[elan]

Not sure whether this should be here or technical.


Bit about me......

Just did my wreck course and are qualified to dive to 40m. At the moment I am using a standard BCD and tank, but am finding I am gas limited for the deeper dives. There is also the concern about not having redundant gas for entering a wreck. On the other hand I do a fair bit of shore diving, and in those cases I normally don't need the extra gas.

So I am trying to work out the best way to move forward. I want to eventually go to a full tech setup, but in the interim I am trying to work out the best way to go forward.

The first option would be to do a sling/stage tank. the advantage of this is that I could continue to use all of the existing equipment, with minimal changeover, but will meet the extra gas/redundant gas requirement. The disadvantage is that I would have to buy the doubles in the longer term, so it is only putting off costs.

the second option would be to go to the full doubles. The advantage is that this is needed in the long term (probably). The disadvantage is that some of my gear (yoke 1st stage) would be made redundant, and it would be harder to convert back to a normal set if I was doing a shallow dive....

Can anybody give me some pros/cons to help me work out the next step?

What would your suggestion be?

Basically, I am going to work on my efficiency anyway, but that won't necessarily fix all of the problems, so I am trying to make plans to efficiently transition, for if/ when I do end up doing more technical diving.

If you plan to do a penetration wreck diving, 50 dives is very little experience to do that. It's more than just buying a bigger tanks, you need to learn huge amount of skills before doing it safe, unless you like playing Russian roulette. I would talk to the local guys who do exactly what you want to do and see what kind of double tanks they use. Then would buy 2 tanks from the same batch so I can pair them up later and would start diving BP/W and working on the skills taking classes like fundamentals or UTD equivalent. Do not rush to kill yourself. Having big amount of gas w/o appropriate skills is asking for troubles

 

[shoredivr]

Well...I dive a "Tech"-ish setup even on my normal single-tank shore dives. I'll explain:

For doubles you will most likely want a Backplate/Wing BCD, something like this. Don't fret, they aren't all that expensive . The good news is that, by swapping the wing and, depending on your configuration, adding a Single Tank Adapter you can use the exact same setup for your regular single-tank diving.

Regulators: Well, it honestly becomes a pain in the rear swapping your regs between singles and doubles setups every weekend (or more often ) so I would honestly recommend getting a set of regulators specific to doubles when you are able to, but in the meantime you can just convert your current regulator to DIN and simply purchase another DIN 1st stage and swap back and forth as needed until you can purchase another regulator set and have dedicated regs for your configurations.

I solved this problem by having H-valves on my 108 singles tanks, so I don't have to have one set of regs for doubles and one set of regs for singles, the same DIN regs go on the doubles and the H-valves. In the cold water here, I find that having redundancy for reg shut-downs in case of freeflows is another reason for the h-valves.

Of course, I also have a set of yoke regs for warm water travelling diving situations. And you can see for yourselves the situation I have with tanks....