BCD- Jacket/vest style vs back inflation

[Stu S.]

You will read posts about "diver streamlining" or a BC that is "sleeker". Compared to other swimming creatures, a diver (regardless of gear) is not "streamlined". A shark or dolphin moves through the sea like a fighter plane through the sky. Even the turtle is speedy underwater. Relative to those, a diver goes through the water like an old bread truck.

There are reasons to buy each type of BC. But... if "streamlining" is your goal, you can compare it to streamlining an old bread truck.

 

[Lorenzoid]

. . .
But... if "streamlining" is your goal, you can compare it to streamlining an old bread truck.

And I thought MY metaphors were funny. You win

 

[jonnythan]

You will read posts about "diver streamlining" or a BC that is "sleeker". Compared to other swimming creatures, a diver (regardless of gear) is not "streamlined". A shark or dolphin moves through the sea like a fighter plane through the sky. Even the turtle is speedy underwater. Relative to those, a diver goes through the water like an old bread truck.

There are reasons to buy each type of BC. But... if "streamlining" is your goal, you can compare it to streamlining an old bread truck.

Even an old bread truck will go slower and use more gas when you increase its cross section by 30%.

There's a reason even tractor-trailers often put aerodynamic fairings on top of the cab.

 

[belairbrian]

I started out with a jacket and dove with it for years. I did switch to a back inflate ( AL Malibu RDS) and for me it is the right choice. For some I dive with a jacket is THEIR preference. Each person has to find what's right for them.

Both of my kids use jacket style and find them quite comfortable.

It seems their is a vocal group of bp/w divers here they feel they have discovered the only TRUE way to dive. Whatever. Heck I can't even figure out where they carry their cans of cheese wiz.

Sunday I will be diving my Black Diamond for the first time. One comment mentioned jackets having more attachment points. I think the Black Diamond has 6 d-rings, 3 quick connects, and loops to add more. also has 3 air dumps. It does seem back inflates have fewer pockets.

BTW, I know 2 divers that use neither a BCD or a wing. Just tank plate and straps.

 

[stakanak]

My my, this is the least threatening discussion on vest/back inflation/BPW I have read yet! Good job all.
I must say though as a newbie it was much easier to learn trim with the back inflate than the vest. I had troubles from the get go with the rental vest BC during my open water cert. After I bought my back inflate it all fell into place...well along with a little help from the peeps on Scuba Board!
Get Wet

 

[Stu S.]

Even an old bread truck will go slower and use more gas when you increase its cross section by 30%.

Maybe so.

Given a bread truck I would rather make a sandwich than drive it fast.

 

[jonnythan]

Given a bread truck I would rather make a sandwich than drive it fast.

Given a bread truck and hundred deliveries to make, I'd like to use the least amount of fuel possible to make said deliveries.. and if I can save 20% of my gas by putting a fairing on the hood I will

 

[Nemrod]

I recently just got back into diving. By the end of the summer I will have my advanced open water certification but I consider myself a very novice diver being that I haven't been diving for so long.

I wanted to purchase a new bcd and really want a less bulky bc so I was looking at the back inflation style as opposed to the vest.

I know vests are better for beginners where back inflation bc's are for more semi-experienced divers. Any suggestions?

One question i have is that when completely inflatable and at the surface how does a back bc differ from a vest?

If you are looking for a travel BC, less bulky, look at either the Scuba Pro Equator which is a wrap around type semi-jacket or the AL Zuma which is a back inflate. I notice on my trip just returning, these were everywhere both as rental and personal choice.

Look, without going into the arguments pro and con, anything back inflate or wing with an aluminum 80 is going to want to roll you face down. The tendency to do so depends upon your weighting, the amount of air introduced into the bladder etc. Keeping in mind that no BC is a rated life jacket nor are they intended to be anything other than a BUOYANCY compensator and so then the ability to provide good trim and stability at depth and compensate for the expected gear load and exposure suit compression is the primary function of a BC. Life support on the surface is not a BC function. I know of no BC aside from the old horsecollar types that might reliably maintain an open airway for an unconscious diver on the surface. Your procedure for this is 1. a good buddy and 2. a good buddy.

N

 

[Leejnd]

Given a bread truck and hundred deliveries to make, I'd like to use the least amount of fuel possible to make said deliveries.. and if I can save 20% of my gas by putting a fairing on the hood I will

See now, you're making the assumption that everyone cares about streamlining and speed underwater. Some people really don't. I dive where there's usually not very good vis and little current, and I'm taking lots of macro photos, so I tend to hang around the same small area for most of the dive. My lack of streamlining really doesn't bother me, and if it's making any impact on my gas use, it's minimal...and not worth it to me to completely replace all of my gear for that minimal benefit.

Point is, again, both configs are valid choices, based on the preferences of the diver.

 

[jonnythan]

See now, you're making the assumption that everyone cares about streamlining and speed underwater. Some people really don't. I dive where there's usually not very good vis and little current, and I'm taking lots of macro photos, so I tend to hang around the same small area for most of the dive. My lack of streamlining really doesn't bother me, and if it's making any impact on my gas use, it's minimal...and not worth it to me to completely replace all of my gear for that minimal benefit.

Point is, again, both configs are valid choices, based on the preferences of the diver.

No I'm not.

I'm making the assumption that I care about streamlining underwater.

By the way, I don't care about speed and didn't say anything about speed. I did not make this assumption in the previous post, but I feel safe assuming that virtually every diver cares about gas consumption underwater.

And I'm not advocating that anyone "replace all their gear." I'm simply stating facts, and stating which gear I think is better. If you don't want to "replace all of your gear" for "minimal benefit" I certainly don't care, and I won't tell you to do so. But this is a thread where a newbie asking opinions and asking which is better. And I think back inflate is unequivocally better.