Diving Sans BC

[Reg Braithwaite]

Reading a rather active thread elsewhere, and the subject of diving without a BC came up repeatedly. Given the loss of wet suit buoyancy when descending to any non-trivial depth, how does the vintage diver compensate? Is it a question of weighting so that the diver is neutral at depth and then compensating during deco?

 

[Nemrod]

Reading a rather active thread elsewhere, and the subject of diving without a BC came up repeatedly. Given the loss of wet suit buoyancy when descending to any non-trivial depth, how does the vintage diver compensate? Is it a question of weighting so that the diver is neutral at depth and then compensating during deco?

What deco?

Rubatex G231, a magic material.

Seriously, as the tank capacity increases and the thermal protection become thicker then the feasibility of no-BC diving decreases. The reason is that as we exceed the ability of our natural BC (lungs) to compensate by more than a few pounds either way it becomes less practical.

It isn't that every dive should be done without modern safety equipment, but the skills to minimize one's dependency upon that equipment remains valid and useful. I think this is lost on many people when the emotions and hyperbole runs out of control and the counter arguments become equally extreme (myself included).

N

 

[maged_mmh]

What deco?

Rubatex G231, a magic material.

N

translation: they use highly pressurized nitrogen filled closed cell neoprene suits rather than ordinary ones. this does not lose buoyancy as much at depth.

 

[herman]

Also, a lot of us dive in locations that do not require much if any wetsuit. I spent a lot of last week diving on Bonaire with a vintage BP (no bladder) and a double hose reg. The wetsuit I wore is a fleece lined skin which is neutrally buoyant and does not compress so all I had to deal with was gas loss. With 80's I weight 2 lbs heavy with a full tank which puts me dead neutral at 1500 psi and 2 lbs light when the tank is empty. I find the +- 2 lb swing very easy to manage...actually I don't even think about it.
I will admit I had a little trouble with the 5mm top I was wearing in Freeport Bahamas in April, with 10 lbs of lead but even at 90 ft I was not so negative I could not control my buoyancy however, it was a little more of a swing than I like.
There are certainly times when a bladder does make sence and life is a lot easier with one and I have no problems grabbing one if I need it.

 

[Nemrod]

I have two Rubatex G231 two piece suits, one is 5mm and the other is 7mm. I can dive both without trouble sans BC. However, I can see how folks with these new soft super stretch suits would have issues. And of course as Herman said, it is easiest with minimal exposure wear.

N

 

[Teamcasa]

I have two Rubatex G231 two piece suits, one is 5mm and the other is 7mm. I can dive both without trouble sans BC. However, I can see how folks with these new soft super stretch suits would have issues. And of course as Herman said, it is easiest with minimal exposure wear.
N

Exactly, we used Rubatex or similar type 1/4" thick suits when diving here in SoCal back in the 70's.
Learning to control your buoyancy took time and practice and some guys even learned how to pick a nice rock up once and a while

Modern BC's help a great deal today when suited up in 10-12MM of modern wetsuit materials.

 

[sross]

I've seen old films of guys (and gals) diving in pre-neoprene days when all you had were suits made of sheet rubber rather than foamy neoprene. No compression at all, (except maybe for little pinches of skin caught in folds of the material?- I kind of wince when I look at those old suits :coolingoff: ) Maybe long undies reduced the suit squeeze problems?

Anyhow, I've dove without BC's many times where they'd cause more problems than they solve, especially when going without a wetsuit. As long as you're with buddies watching out for each other, I've never felt unsafe.

Speaking of going sans wetsuit- maybe I could have used one of those old sheet rubber suits a few times when the water was warm enough to not need a wetsuit . . . probably would have prevented a few stings & abrasions . . .

 

[John C. Ratliff]

Buoyancy compensation is just that, compensating for the loss of buoyancy of the wet suit. A sheet rubber dry suit did not loose buoyancy. I dove one for years, and sometimes used it with a wet suit under the dry suit. I put a power inflator on it, and the suit became my BC when the wet suit pants (Farmer John) compressed). I wore a Dacor life vest with it, but not for BC purposes. Here's what it looked like:

I did a lot of experiments in the 1970s with buoyancy control, and wrote about it too. One dive in Clear Lake, with a 1/4 inch full wet suit, I wore my normal 12 pound weight belt (neutral at the surface), put a butterfly knot into the anchor rope, and took off the weights at 30 feet. I was completely neutral, and could go up and down without problems. It is only in the last 30 feet that the wetsuit regained its buoyancy, due to the full expansion of the neoprene. So before surfacing, I put the weight belt back on, and went to the surface. It was one of the more enjoyable dives I've ever made, as I did not have to fiddle around with the buoyancy. Here's a photo of me in Clear Lake (headwaters of the South Santiam River, in the Oregon Cascade Mountains) in the early 1970s. I'm weighted correctly for the depth, of about 20 feet.

John