Underwater Wakulla
By RUSTY MILLER
I ended last week’s article on the modern regulator and how important it is to maintain their service. I said I would look at the modern BCDs vs. not so modern BCD’s. Let’s begin with the older style of BCD; the BCD really came into its own back in the early to mid-70’s for the recreational scuba diver. Some of the first ones looked like the old Coast Guard life jacket. The difference was you had to inflate the bladder manually aka your mouth. Shortly after that they introduced the inflator button so you could use that to inflate it. That part of the BCD hasn’t really changed over the last 50 years.
The BCD itself sure has changed, since the technology has changed so has the ways that BCDs look, feel, and work. Let’s take a look at how they are constructed. The bladder is a modern marvel compared to what it started at back then. With the advent of PVC substrates, it has eliminated the need for any petroleum products to the system. Instead of canvas they use a Cordova type material that is much more rugged and last double the life of canvas.
Then you add injection mold making with some of the very tough and durable plastic that is used for the quick disconnect buckles and you have on your back a proverbial modern marvel of technology. With the modern BCD you have integrated the different types of D rings - some are plastic but most are stainless steel - to hold your accessories like flashlights, reels, and GoPro-type cameras. Some BCDs have a pocket or two so you can put your dive tables, sea shells, and even attach a dive tool like a small dive knife.
The modern BCD has the capability to have weights into the waist of the unit that is known as the integrated weights system BCD. The integrated weights system allows for the weights to be put into a pocket of sorts and usually they have a type of release system that is attached to the pocket itself then it fits snugly into the BCD on each side then snaps into place. If, in an emergency, you need to remove or ditch the weights you simply pull the handle and drop the weight pocket.
There are several different styles of the modern BCD: you have the jacket with a harness BCD, there is a full harness BCD where the lift bladder is connected to the tank harness, and you have the semi jacket harness BCD. The first type has the bladder that is connected to the actual harness that holds the tank and has part of the bladder routed under the pockets of the BCD so when inflated you feel the air under your arms and it allows the diver to stay in a vertical head above water position.
The full harness BCD where the bladder is attached to the tank harness is more for single and or dual tank connection and most of the back bladders are an oval shape so when fully inflated they give support to the lower portion of the tank(s). The main drawback to this type is unless you are specifically trained to use it you will not like it because when fully inflated it will try to force you face down in the water. The big advantage this type of BCD has is that it allows you to have more equipment attached to the bare harness for more technical diving situations.
The final type I want to talk about is the semi jacket harness: this type is a very unique style that gives you the best of both types. The bladder is attached to the harness and it wraps a little around both sides at the bottom of the BCD so when fully inflated it allows the user to slightly lean back to be at a more vertical position so you don’t feel like your face is being forced down to the water. It is a very comfortable BCD and a very popular one but it does require a small bit of training to get used to.
The obvious choice that I recommend for a diver especially a new diver is the first BCD because of the way it is designed to keep your head up above the water when it is fully inflated. Then when you have made yourself comfortable diving you can move up to the more technical based BCDs. Believe me when I tell you that you will use more than one type of BCD in your diving experience.
Russell Miller is the manager at Wakulla Diving Center in Medart. NAUI Instructor #59999