Basic BC Education

[n733lk]

Can someone direct me to a good basic BC education site or provide some helpful insight as to the differences among BCs.

What should a newbie consider when evaluating BCs? Minimum specs? Brands?

What about used BCs? Single Tank-Double Tank? Plates? Wings?

 

[Arkman]

I don't know of any site in particular, but if you post what your skill level is and what kind of diving you do and where, anything else you think would be relevant. I'm sure lots of people will help give you info on what bc is right for you and why.

 

[n733lk]

My diving will most likely be lakes and rivers, with an occasional "real" diving trip in the Big Pond. Experience level is -3. Just in the process of exploring my equipment options.

Thanks.

 

[Crush]

In common SB usage "BC" refers to a buoyancy compensation devices which lack a hard plate - BCs can be rear-inflate or inflate also around your torso (the latter are often referred to as jacket style BCs). On SB BP&W is used to describe a minimalist system with a hard plate and a wing.

Most BCs can't take doubles. BP&Ws can accommodate doubles with appropriate mounting hardware. Usually different lift wings are used with singles and doubles.

If you are going to travel to your dive sites on a plane get something that packs well. Usually for a BC this means no integrated weights - use a belt.

 

[fjpatrum]

Can someone direct me to a good basic BC education site or provide some helpful insight as to the differences among BCs.

What should a newbie consider when evaluating BCs? Minimum specs? Brands?

What about used BCs? Single Tank-Double Tank? Plates? Wings?

This is probably the best resource around for finding the information you seek.

Jacket BC: a "vest" that wraps around the sides of your body and generally has air bladder that also wraps around your body. This is what most people learn in, at least in the USA.

Back Inflate BC: a system with a harness that has an air bladder limited to just your back, IE not wrapping around the sides of your body. A lot of more experienced divers go to some form of back inflate eventually. May or may not have integrated weight system.

Hybrid BC: generally a back inflate that has a full vest front and an integrated weight system.

BP/W: A hard (or occasionally soft) plate system with a harness that a "wing" bladder attaches to. This is a back inflate system that got general acceptance amongst the tech diving crowd and is creeping into the rec diving crowd. (Apparently this creeping is mostly due to scubaboard proponents of the bp/w system.)

All will allow you to dive standard rec open water dives. Arguably all will allow you to dive any type of dive you want but the tech gurus will bitch and moan if you try to do tech dives in a jacket bc. Such is the way we mark our territory, I guess, just like dogs peeing on trees.

With regard to backplates, a plate is a plate. They are mostly standard hole spacing these days and fit most any wing you buy mix and match. I hear there are a few exceptions to that rule, but I don't know what they are off-hand. Plates come in Aluminum, Kydex, Stainless Steel, or you can be cheap and make your own out of PVC. (That's what I did for my first one.)

Buying a used BC is totally acceptable and, from my perspective, a good way to get the gear you want at a much reduced price. What to look for? Negatives: frayed or faded nylon/straps. Make sure the hoses and plastic parts aren't brittle and that the BC will hold air for 20 minutes or so. (Tiny leaks aren't bad and even most big leaks are repairable if you have that inclination.) I wouldn't recommend buying things with big leaks as that's likely to indicate poor maintenance that might mean other hidden "dangers".

As for minimum specs, your big concern is the amount of lift you need. If you're looking at back inflate/modular systems like zeagle products or bp/w, check out the "ultimate lift calculator" thread as a sticky at the top of the BC subforum. It will tell you what amount of lift you actually need. Most jackets give 35-40 pounds of lift, which is more than enough for anyone in singles. Older jackets occasionally have more realistic lift, like 18-25 pounds, but are often overpriced by current owners and not worth it. That said, look at your local craigslist and ebay as well as the classifieds here and at decostop. Good deals can be had.

Most any brand BC you will find these days will be fine. Older BCs have less standard parts so if you're buying used, consider that. Stick with brand names you can still buy new and you should be reasonably safe.

 

[TSandM]

I don't know of any site that discusses the topic thoroughly.

Basically, a BC consists of an air bladder which allows you to compensate for two things: The gas you are going to exhaust into the water, and the buoyancy lost by your exposure protection as you descend. The first "buoyancy compensators", as I understand it, were milk jugs with air in them, used by cave divers. So you can see that it doesn't take a very complicated piece of equipment to do that job.

The air bladder can come in a variety of shapes, and it can either be an integral part of the entire rig or it can be a modular and removable or switchable part. The rest of the BC consists of some method of securing a tank, and a harness that attaches the rig to the diver.

There are basically two major types of BCs: Jackets, and back-inflates. Jacket BCs have an air bladder that extends into flaps that wrap around the diver. When you inflate the bladder fully, the air forms a ring around the diver's torso. These BCs are very nice for floating on the surface, but some people find the constriction of the inflated bladder around the body uncomfortable. These BCs tend to have a lot of fabric, weigh more, and can have more intrinsic buoyancy (in other words, you have to carry more weight to sink the equipment itself).

Back-inflate BCs come in two flavors, too: One type is a fully integrated setup, where all the pieces are assembled and it does not come apart. The other type has a harness, a plate or other stabilizing device, and an air bladder or "wing". Both share the characteristic of having the lift behind the diver, and the bladder does not wrap around the body. The integrated rigs may come with pockets, and may have weight-integration. The modular units will only have those things if you purchase and install them.

Selection of a BC is a very personal thing. It is critically important that the BC fit well and hold the tank stable in the middle of your back. In my experience, all-fabric BCs do not do this very well -- you need some kind of plastic or metal plate, either as part of a modular system or build into the BC itself, to hold the tank still. It is often difficult to know whether a BC will do this, just by putting it on and walking around in it in the shop.

You want enough lift in a BC to compensate for your gas and your exposure protection, which generally means that people diving in cold water will need larger air bladders than people who are only diving in the tropics. Having excess lift makes the BC bigger, heavier and sometimes harder to vent. Not having enough lift can mean that you will either lose your rig if you have to take it off on the surface (not enough lift to float the tank and weights) or, in the worst case, that you cannot establish neutral buoyancy at depth, once your neoprene has compressed.

Weight integration is a personal choice. It means you don't have to wear or remember a weight belt or harness, but it also can limit your choices of where you put your weight, and make it difficult to balance yourself underwater. I don't like weight integration, myself, because I like to keep the total weight of the rig low, to make it easy to move around on land. Keeping my weights and my tank separate makes my life easier. (It is often VERY difficult to insert weight pouches into a BC once it is mounted on the tank and sitting on the boat.)

Manufacturers introduce all kinds of bells and whistles to gear, to make it seem "new" and to be able to charge higher prices. Be careful with your selections, and make sure that any features you find attractive are actually things that WORK -- for example, some BC pockets are almost impossible to access while you are actually diving.

One good way to figure out what you might want to own is to look at what people who dive where you are diving are using. If there's a theme, it may be because folks have figured out that that kind of equipment works well for their diving conditions.

 

[n733lk]

I'm already 2 steps ahead of where I was this morning. Just trying to get all the lingo and multitude of gear questions sorted out.

Thanks!

 

[Jim Lapenta]

One thing to remember is that if you are in the process of getting certified your instructor should provide you with at least one lecture on equipment and a good one will go over all the types of BC's that are commonly used, what they components are, and how to choose the right on for your diving. Don't let yourself be talked into something you don't really need or cannot afford. Used is a very viable option.