80's or 120's?

[scubaduba22]

I'm new to diving but want to make a good investment on gear upfront . The local dive shop owner is pushing a Hollis BC at me but I'm hesitant because you can't dive doubles with it (Hollis ATS). He and others at the shop are saying they don't dive doubles, they dive with a single 120 which would work on the Hollis ATS. I know most advanced divers/technical divers say BP/w is the way to go, so this question is more about the use of 80's vs. a single 120. Any information on the advantages/disadvantages of diving a single 120 is greatly appreciated. Also, do any of you actually use a single 120 on a regular basis. Most of my diving is in warm water from the Carolinas to the Caribbean if that helps.

 

[ucfdiver]

There's so many variables that go into this that we can't really tell you what to get.

I'd say the 80 would be nice because it's lighter, cheaper, and most of your dive buddies will have them (so you couldn't use the extra air if you had it).

The 120 would be nice for a doubles rig in the future if you went that route, and obviously if your dive buddies are diving them as well, then you obviously get 50% more air.

 

[Otto]

I own 2 sets of lp120 Fabers as doubles, and 2 lp120 faber singles. I use a bp/w as I don't care for a bc. If you are certified, see if you can rent the combo that they want to sell and test dive it. Please note that the 120 cuft tanks are tall, and that all the different brands and pressure ratings of cylinders for a given size will likely have differnt bouancy characteristics, and they weigh about 48 to 50 lbs each.

If you've never used one see if you can rent or borrow a bp/w and dive it a few times before you start spending.

 

[scubaduba22]

ucfdiver, do you think it's even worth getting the BC that won't do doubles? Or are you saying that most people will dive a single 80 at a time so the BC that does singles is worth it?

 

[battles2a5]

You are new to diving, so you have some time before you need to worry about doubles. That being said, if you foresee that you will be getting into technical diving in the future, going w/ a BP/W would be a wiser purchase than the Hollis rig. If you are just looking for gas you can get the Hollis (but I would still get a BP/W). Going to doubles offers safety in the form of a redundnat gas supply but you also get 3 times the failure points that you do on a single cylinder. Like any other piece of equipment they are a tool and you need to be properly versed in their use. Going to doubles just to get the gas or to compensate for a high consumption rate is not a good idea, IMO.

 

[ucfdiver]

ucfdiver, do you think it's even worth getting the BC that won't do doubles? Or are you saying that most people will dive a single 80 at a time so the BC that does singles is worth it?

I think a bp/w is the best choice, I see no valid reason to go with a BC. Since most people dive a single 80, that will be the amount of gas you'll be able to use typically (assuming your buddy's breathing rate is close to yours), so I dive an AL80 when I'm diving with others who are using them, and I'll dive with my double LP108's when I need more gas (IE a cave dive).

 

[TSandM]

I'm basing what I write on the fact that you say you are new to diving.

What you really need is a BC that fits you and is comfortable, and that you understand and can safely and readily use. It should hold a single tank stably on your back. It should fall within your budget, and it should be well enough designed that its function isn't compromised by poor construction.

You have a LOT of dives ahead of you, before you think about staged decompression (or any other technical diving). You have two choices -- You can buy gear now that is comfortable and useful and suitable for the diving you will likely do for the next year or two, and realize that you may well end up replacing it at some point if your passion for diving persists, and your ambitions expand. (Realize that, for the VAST majority of divers, this point never comes.)

Or you can buy gear that is flexible enough that you can carry it into almost any diving you eventually decide to do. You don't lose anything by doing that; you still get a BC that's comfortable, fits you, and you can easily use. You may have to find someplace to stow your peripheral stuff (like put pockets on your exposure protection, or buy them to put on your waistband. It costs more.). And you'll have to figure out what to do with your weights. You can use a belt, a weight harness like the DUI weight and trim, or add weights to your backplate and cambands, depending on how much you need and what the optimal distribution is.

Any dive shop can be forgiven for recommending the gear THEY sell and they know. It may or may not be the optimal gear for you. For every diver who goes from open water to technical or cave diving, there are probably fifty who dive a comfortable jacket or back-inflate BC for all the dive they ever wish to do. The divers who are active posters on Scubaboard are NOT a representative cross-section of the diving world!

Having rambled at length, I'll admit that I have three backplates and three different wings, and have no desire to change to anything else. (But I didn't start out there.)

And to finish, as far as tanks go, plan on diving a single tank for quite a while (you should). An Al80 is really not an adequate gas supply for any dives below about 80 feet, so a larger tank is probably a very reasonable idea.

 

[scubaduba22]

Thanks folks. Very good advice! That's what I came on here for...good advice.

 

[Colliam7]

…so this question is more about the use of 80's vs. a single 120. Any information on the advantages/disadvantages of diving a single 120 is greatly appreciated. Also, do any of you actually use a single 120 on a regular basis. Most of my diving is in warm water from the Carolinas to the Caribbean if that helps.

An AL80 is really not an adequate gas supply for any dives below about 80 feet, so a larger tank is probably a very reasonable idea.

Very good point. I started with an AL80. Moved to a single 120, because I wanted more gas for single tank wreck dives off the Carolina coast, in the 80&#8211;130&#8217; range (i.e. where most of the interesting wrecks lie). Diving the single 120 is great for that purpose. Allowed me to more closely align my gas supply with NDLs, whereas with a single 80 the limiting factor on dive length was gas supply. HP120 is a bit long but not a problem. Going HP steel allowed me to drop weight off my waist. If I did it over though, I would go with a HP130, not a 120, as a single tank. A little more gas, a little more weight, slightly better trim characteristics for people <6&#8217; (I am 5&#8217;10&#8221. If you go 120, you will probably love it. Same for a 130.
Rest of the story. Bought another 120; doubled them up. Use my single 80 for a deco bottle. Bought some double 80s as well. Looking way, way ahead in your diving experience and training, and presuming you ultimately go BP/W, double 80s are also a nice coastal, wetsuit diving, rig as well. Nice trim characteristics, plenty of gas for recreational dives.

 

[pescador775]

Duba, have you seen this thread?
http://www.scubaboard.com/forums/hollis/235931-hollis-bcds.html
I'm kind of a bug on streamlining. I never use double bag rigs or "busy" equipment like the ATS, and most wings flap in the breeze. I have not had a chance to inspect the Hollis personally but this thing shown on the referenced thread is a closed loop, not just loopy like regular wings. I use an old back inflate which was made by Seaquest (Dimension 3). It's only about 25-30 pounds lift but that is plenty for me. It's main feature is that it practically disappears until needed and the adjustment system is unusually sophisticated compared to backplates and cumberbunds which use a crotch strap. However, it might be nice to have a sturdy old style set of straps and plate as shown in the thread. That is, so long as you can accept the crotch strap. You'll have to don the weight belt over that strap unless you have some kind of belt which can be slid out from under.