by B. N. Sullivan
One of the earliest posts in The Right Blue tells about our training as divers. In the post I mentioned that I first learned to dive in 1970. That's right -- 38 years ago!
Diving has changed a lot since 1970, mostly because of improvements in equipment. We decided it would be fun to review the progression of those changes for our readers. This exercise will take several posts, so bear with me.
To start things off, have a look at the picture at left. That's me, in 1970, when I was a newly minted diver. (No, I wasn't angry -- the sun was in my eyes!)
When we first unearthed this old photo, I had to laugh. That red thing I'm wearing looks like a life vest pilfered from an airliner, but it's not. Known as a 'horse-collar' vest -- for reasons I'm sure are apparent! -- it was used primarily for surface flotation.
Dive gear is very heavy, and can be cumbersome. Swimming on the surface with, among other things, a metal tank on your back, and lead weights arrayed around your waist can be incredibly daunting at times. When the flotation vest was inflated, it helped counteract that weighed down feeling, and enabled divers to keep their heads above water while waiting for a boat, or swimming to shore. Those horse-collars were not very comfortable, however.
The vests had little CO2 cartridges inside. The CO2 could be released to rapidly fill the vest in an emergency, but most of the time, we blew the things up by puffing into the little inflator hose. The CO2 cartridges were single-use only, and it was expensive to replace them all the time, so we really did restrict ourselves to using them only when we were struggling or in a jam.
Fortunately those dopey horse-collar vests with the CO2 cartridges are no longer used by sport divers. They've been replaced by buoyancy control devices (BCDs for short), in the form of vests, jackets, or pouches (called 'wings') attached to a harness. These days, BCDs are inflated at the push of a button, with air supplied from the scuba tank through a special low-pressure hose. Divers can and do still use the BCD for flotation on the surface, but they also make use of the device underwater. By adding a little puff of air to the BCD at depth, divers can adjust their buoyancy, compensating for the weight of their gear.
The next thing I spotted in the photo was the tank -- or rather the valve on the tank -- and the regulator. We were using "J-valves" on scuba tanks at that time. There was no such thing as a submersible pressure gauge, so we could not monitor how much air we had left in our tanks once we entered the water. Tanks fitted with "J-valves" had a mechanism that blocked the diver's air supply at a certain (low) pressure level. The valve had a lever on it that the diver could pull to release the remaining air, known as the 'reserve' air. Believe me, that reserve wasn't much, but it would provide a few more breaths -- usually enough to get to the surface (we hoped!).
The regulator in the photo is a single-hose demand flow regulator, which was a pretty sophisticated rig at that time -- compared to, say, a double-hose regulator. Those old double hose regs required the diver to sort of suck the air out of the tank! We still use single-hose demand flow regulators, but the ones we have now have numerous ports on the first stage -- the part that attaches to the tank valve. To those ports we attach various pieces of gear, including power inflators for our BCDs, submersible digital pressure gauges so that we can continuously monitor our air supply, and one or more extra second stages -- the part of the regulator that has the mouthpiece -- to facilitate sharing air with a dive partner if need be.
Note the clunky old analog depth gauge that I'm wearing on my wrist in that photo. Key pieces of dive management gear in those days were the depth gauge and the dive watch or timer. Those relics now have been replaced by digital electronic decompression computers which continuously sense depth, keep track of elapsed time, and recompute every few seconds how long we can safely remain at a given depth -- as well as many other bits of information that I won't go into until another time.
Even our wetsuits have changed. The one I'm wearing in the photo had no lining and was extremely difficult to get into -- just rubber against skin. Everyone carried a box of cornstarch or a can of talc in their gear bags then. We applied it liberally before donning our suits, but it made quite a sticky mess, and often didn't help the process all that much. These days our suits are lined with Polartec or other soft materials that make them as easy to slip into as a pair of jeans.
Ahh, the good old days!