Diving Safely Without A BC

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Yes, they must. Seriously though, there might be a requirement for a flotation device for snorkeling but I didn't see anyone using one.

You remind me of a snorkel excursion that I accompanied a friend on in Cancun a while back. Every snorkeler was handed a life vest and told they had to wear it by National Park rules
Shortly after entering the water the guide had everyone watch, and he dived to the bottom to point something out.
I followed to get a closer look.
When we returned to the surface the Mexican guide said "your a diver", pointing to the hard orange life vest I was wearing, he said "no one but a diver can ever get to the bottom.in one of those."
 
There was discussion a while back on this thread of use of the "Mae West" life vest. The first photo here is of that vest. Note that the oral inflator is a very small diameter hose, which is a "push to inflate" spring-actuated valve. You pushed it onto your your teeth while holding it in one hand to inflate it. There was no overpressure relief valve, so it is assumed that you would inflate it on the surface if there was a problem. There was also a CO2 inflator mechanism for actuating it in an emergency.

The second two photos in Clear Lake, Oregon (headwaters of the McKenzie River) are of a diver properly weighted, and of myself in an Aquala dry suit (photo using my camera by Bruce Higgins). Note that weighting can easily be accomplished, even in a dry suit, without use of a BCD.

The last photo, the group shot from Santa Barbara's surf area, is of my NAUI Instructor Training Class (ITC) in 1973 (if my memory is correct). Note that we are all wearing the "Mae West" style of life vest, and not a buoyancy compensator vest. Those were forthcoming, but not at that time required. I'm the lower right-most diver in the photo.

My method of checking buoyancy in a full wet suit is to be neutrally buoyant (vertical in the water, with my eyes out of the water) on a full breath at the beginning of the dive. Exhaling initiated a descent. This made me neutrally buoyant on my return with a tank at about 500 psig (single steel 72).

Most of the buoyancy change to any wetsuit happens in the first 60 feet of water. After that, the neoprene is compressed enough that the buoyancy doesn't change much at all. So deciding on an arbitrary depth limit for diving without a BC is just that, rather arbitrary. In Clear Lake, I have taken off my weight belt, hung it on the boat's anchor line at about 60 feet, and swam around perfectly neutrally buoyant. When it came time to ascend, I simply took the weights off the line, untied the Butterfly Knot*, and swam to the surface. But swimming at depth sans both weight belt and a BC was a magnificent experience.

SeaRat

*Every diver should know how to tie a butterfly knot (or butterfly loop) into a rope. It comes in handy in many, many circumstances.
 

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:lolabove:

They do seem to have a lot of park rules--some good, some maybe not so good.

That must be what a "snorkel vest" is for. I've often wondered what they were.


One thing I definitely don't miss from the old days is the round mask.

In response to Ratliff: the vest I still use is much more modern--it does have a pressure relief valve. It was made by Voit. My other vest looks just like your picture.
 
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Like you said, Very Cool!

Great tutorial video too. Being the kind of guy I am I checked out what I have laying around and came up with: a regulator mouthpiece, a 1/2" PVC slip joint tee fitting, and some air hose that measures about 3/8" ID. I can't wait to try it out in the pool later this week when it has water in it.

WP_20160514_001.jpg


I used electrical tape to take up the empty space inside the fitting where the hoses go but a 1/2" to 3/8" reducer on each end just might fit nicely. This version required no tools except for cutting the hose pieces. The regulator mouthpiece fits so snugly that a cable tie does not appear to be necessary. My hose is kinda stiff which might be a disadvantage when using it for scuba diving. If this works for me then I won't mind spending 62 cents on reducers ;)
 
there was a discussion A while back on this thread of use of the "Mae West" life vest. The first photo here is of that vest. Note that the oral inflator is a very small diameter hose, which is a "push to inflate" spring-actuated valve

I had an earlier version Mae West that had a modified tire valve, it was three or four turns to to open or close. The CO2 cartridge would fill it on the surface so it would not overinflate, because there was no OPV. Regardless of what depth the CO2 cartridge was actuated the vest would not overinflate, however it was was useless for buoyancy if detonated very deep.


Bob
 
I just noticed the links were messed up in the previous post. The first 2 links went to the same offshoot thread.

This is the link to the original posting on the loop snorkel: Very Cool DIY Dual-Tube Snorkel for about $6

I went back and edited the original post #71 to have the correct links.
 
My method of checking buoyancy in a full wet suit is to be neutrally buoyant (vertical in the water, with my eyes out of the water) on a full breath at the beginning of the dive. Exhaling initiated a descent. This made me neutrally buoyant on my return with a tank at about 500 psig (single steel 72).

Curiously, SeaRat's method is the method I, too, was taught, in 1986, when wearing a BC (a Scubapro Stab Jacket). I described it in detail in an old post here: Failed BCD pressure relief valve.

Safe Diving,

rx7diver
 
I love how these no BC threads eventually will round up all the usual suspects that have dived this way in the past or currently dive this way.
And in the beginning of the threads there are always a few naysayer modernists that will come in with the claim of how unsafe it is and "why".

Here's my take.
The modern jacket BC has grown a life of it's own and become a monster from what it's original intention was. Originally all it was supposed to do was add a little air at depth to compensate for heaviness at depth with thick wetsuits. People with no wetsuits or really thin wetsuits didn't use them for quite some time before the industry decided to make it a blanket policy to require them in training.

But more to the point, the modern BC has gone from being a compensating device and luxury item to a overused, depended on, life and death item that is so abused, and diving has fundamentally changed because of it.
Back in the old days when people dove with out BC's and learned the fundamentals of weighting and watermanship first, then used a BC it was only used at depth and it was considered a luxury item.
Now the use goes from the time they hit the water to the time they get out. The biggest problem I see is the BC allows for a buge amount of overweighting which most new students are oblivious to. I think a lot of modern instructors are also oblivious of the dangers of overweighting and relying on a BC to cover for this problem, after all this is where OW students are gleening their info. This culture of ignorance and loss of fundamental understanding of proper weighting has been long gone for many years now and the original information lost. So as a result we see new instructors regurgitating the same mis info that was fed to them by instructors who were fed the same thing. At some point the info got rinsed out and has not been reformed.
Todays BC's allow for "elevator" diving which is relying on an inflated wing to stay on the surface as soon as hitting the water, during the surface swim, during the dive at all depths, during ascent, during the safety stop, and then to stay bouyeed and floating on the surface after the dive. Anything happens to the air cell during any of these stages results in the diver suddenly having a very real problem with dropping like a rock which more times than not they are not trained for. To compound this problem many weight pockets built into the BC's have squeeze clips which can take a little fanagling to get loose. It used to be that if a no BC diver got in trouble they just dumped their belt and went up, these days it's not so easy. Current training relies on nothing going wrong with the air cell on a BC.
I see some of this modern equipment as a benefit to manufacturers, dive shops, and instructors way before I see it as a benefit to the divers stuck using them.

My philosophy is that divers could greatly benefit from learning to dive with no BC either as a diving style or simply just as a proper weighting learning tool, then returning to using a BC with this new knowledge. When diving without a BC you get a crash course on proper weighting the moment you hit the water. Most people can't believe how much weight they can actually shed when it comes down to the "proper" amount. Essentially to dive with no BC the diver must be weighted so that at the end of the dive they are neutral at a selected depth. Everything else revolves around this goal. So for me, when I dive with no BC I use a 7mm. I weight myself so I float on the surface with a full 72. To decend I pitch foreward and swim down breaking neutral at about 10 feet. I can dive to about 40 - 50 feet for 30 to 45 minutes. Coming close to the end of the dive I'm already back close to shore in about 20 feet of water. I'm neutral at about 20 feet and being that my NDL's are minimal I don't worry too much about needing to hold a perfect 15' safety stop. If I get into trouble at any stage in the dive I know to simply drop my weights and make my way up. Without an air cell I won't rocket to the top, this is a huge misconception. Wetsuits inflate very slow, so even if a weightbelt is dumped at depth the acsent is fairly slow and controlled. It's very simple.
So with this info, a diver who has learned proper weighting through the lack of BC which gives them nothing to hide behind, they learn very clearly what proper weighting looks and feels like. After this if they return to using their BC's for deeper dives they understand crystal clear what a BC is supposed to do and they also understand the current culture of abuse.
Amazingly, they also get revelation on streamlining and an automatic self realized lesson on drag and hydrodynamics when all that padding and crap is removed.
 
Wetsuits inflate very slow, so even if a weightbelt is dumped at depth the acsent is fairly slow and controlled. It's very simple.

A very important concept to understand, the dreaded rocket ride to the surface is due to the air in the BC, not your thermal protection. Eric and I dive the same waters, SCUBA and free, I'm in a 7mm farmer John and have the same experience surfacing.

I forgot my weight belt one day when Abalone (free) diving. To get to depth I used hand over hand down kelp to depth. At 35' I could maintain move around by kicking down as well as the direction I wanted to go. The return to the surface was faster than with a belt on, but nothing to be alarmed about, even if I was on SCUBA. The ascent could have been slowed if I flaired out on the way up, but free diving I didn't need to.


Bob
 

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