Perfect buoyancy

[Angelo Farina]

When I started diving in 1975 there was no BCD. We were using twin cylinders, and deco was the norm. Choosing proper weighting was very important, for avoiding to be too negative when at 50m depth the wet suit compresses and the cylinders are yet full of 5 kg of compressed air.
Of course, at the end of the dive and at deco depth one becomes significantly buoyant. The solution was simple: the deco cylinders deployed by the boat when the group was emerging were attached to a bar, together with additional weights. After reaching the bar (usually at 9 or 6 meters, depending on the planned deco) we did attach the additional weights to our belts, and perform the deco in neutral asset.
Some years later I did get my first BCD, an annular Fenzy (you see it in my avatar photo).
But I continued to dive the same way, with little weight, keeping the Fenzy always empty, and relying on the additional weights deployed together with the deco cylinders for buoyancy control during deco.
Here in Italy there is still now a group of divers who do not use any BCD and carefully tune their weights for diving with minimal equipment and friction, using long freediving fins, no suit, or perhaps just a thin wet suit with perfectly smooth external surface (no fabric outside the neoprene) and nothing hanging around.
Here their manifest (in Italian): http://solitarydiver.altervista.org...RA-Lasostenibileleggerezzadellasemplicita.pdf

 

[TMHeimer]

You're wearing a lot less weight than me (at 42 pounds), so 1/2 pound weights may cause a bigger change in your noticeable buoyancy (may not, don't care about the exact physics).
I'll throw out that my weight needed has varied from 37 to 42 pounds and at times I have used one pound weights, but never 1/2.
At 37 pounds and only as low as 2 pound weights I at times had something like 8 pounds on the left side of my pocket weight belt and 6 on the right side. I never noticed any tendency to lean to the left, probably with all that total weight (10 pounds each BC pocket, 4 pounds each shoulder trim pocket).

 

[BRT]

How much air do you have on safety stop? Remember that someday you may be on a safety stop with enough nitrogen that you really need the safety stop, and with less air in your tank. Being in this situation made me want to dive with a little extra weight. And the "bean burrito" problem is not a fake.

 

[Ukmc]

Wow. There is a huge variation to how much weight everybody wears. It is quite amazing.
I have always wondered what happens to gas in the stomach and colon upon ascend. I assume “bean burrito” comment insinuates that, but maybe I am totally wrong and missed something. I guess if one has a bowel obstruction, they really can blow up...
anyhow, as I was working with decreasing my weight, I would get 500psi tank and see if I can hang out at 12-15 feet without trying to squeeze all the air out of my vital capacity. I now dive with no weight in fresh water and 6 lbs in salt. I am usually at a safety stop around 750 to 500. I feel great through 750. I feel a little light but manageable around 500-600. I suppose if I ever get down to 300 it could be problematic without additional weight or a line. It is an intriguing idea to have extra weight available for a safety stop. Has anyone seen this practice in US or Caribbean? Thank you again for all of your expertise. It is cool to hear what everybody does based on geographic location or historical perspective or personal experience. I love this forum.

 

[rongoodman]

When I'm at my safety stop and go a little head down I can feel a fistful or so of air in the bottom of my wing. I wouldn't want to have to have it shrink wrapped around the tank in order to hold the stop.

 

[scrane]

Worrying about an extra pound or two is just silly.

 

[johndiver999]

Wow. There is a huge variation to how much weight everybody wears. It is quite amazing.
I have always wondered what happens to gas in the stomach and colon upon ascend. I assume “bean burrito” comment insinuates that, but maybe I am totally wrong and missed something. I guess if one has a bowel obstruction, they really can blow up...
anyhow, as I was working with decreasing my weight, I would get 500psi tank and see if I can hang out at 12-15 feet without trying to squeeze all the air out of my vital capacity. I now dive with no weight in fresh water and 6 lbs in salt. I am usually at a safety stop around 750 to 500. I feel great through 750. I feel a little light but manageable around 500-600. I suppose if I ever get down to 300 it could be problematic without additional weight or a line. It is an intriguing idea to have extra weight available for a safety stop. Has anyone seen this practice in US or Caribbean? Thank you again for all of your expertise. It is cool to hear what everybody does based on geographic location or historical perspective or personal experience. I love this forum.

I strongly disagree with a protocol that involves the ascending diver being provided some extra lead on a line for a recreational dive. It makes the dive more dangerous, more complicated and is unnecessary.

It makes far more sense to carry enough lead yourself and thus being able to ascend at any time and any location and still perform a comfortable stop. If/when you begin to use an smb (on a reel or spool or some kind of line) you are going to NEED some extra lead to actually pull down on the string to ensure that the smb stands upright.

You could maybe swim down the whole hang or something, but that is an unnecessary situation that should be avoided.

Another contingency in some situations is that a boat is turning a prop over your head. It might literally be a life or death importance to be able to hang at 10 feet and wait for two minutes with near zero air in your BC. Playing a game of trying to use the absolute minimal amount of lead, actually limits your options and your ability to deal with various emergencies that are well within the realm of not unlikely.

Also, if you are wearing a wetsuit and you have too little lead, you can often perform the safety stop a little deeper - maybe 20 or 22 feet. At this depth, the suit compression will be sufficient to offset some degree of underweighting, but if you are wearing a dive skin or something, this potential remedy is NOT applicable because there is no suit compression to exploit for your benefit.

You want to be able to hang at 10 feet and not float up and breathe normally and have an effectively empty tank AND be able to hold down the end of an SMB. Whatever lead that takes will be safest. Trying to skimp on 2-3 lbs is not a good game to play.

 

[BRT]

Wow. There is a huge variation to how much weight everybody wears. It is quite amazing.
I have always wondered what happens to gas in the stomach and colon upon ascend. I assume “bean burrito” comment insinuates that, but maybe I am totally wrong and missed something. I guess if one has a bowel obstruction, they really can blow up...
anyhow, as I was working with decreasing my weight, I would get 500psi tank and see if I can hang out at 12-15 feet without trying to squeeze all the air out of my vital capacity. I now dive with no weight in fresh water and 6 lbs in salt. I am usually at a safety stop around 750 to 500. I feel great through 750. I feel a little light but manageable around 500-600. I suppose if I ever get down to 300 it could be problematic without additional weight or a line. It is an intriguing idea to have extra weight available for a safety stop. Has anyone seen this practice in US or Caribbean? Thank you again for all of your expertise. It is cool to hear what everybody does based on geographic location or historical perspective or personal experience. I love this forum.

I've been in the situation, 200# of air and really wanting to hang and make it last because I am right on the edge of deco on a liberal computer. Swimming down to hold a stop is not a good way to conserve air. In addition different tanks have slightly different buoyancy, you may get a light one. You may have a little gas in your gut. I choose to dive heavy enough that this is not an issue. At times I have started dropping weight "because I can hold fine at the end of a dive". Eventually I end up light and think about how it would be if I really needed to breathe the tank down. Then I put on a couple extra pounds. I really don't notice it diving 4-5 pounds heavy.

 

[CT-Rich]

Wow. There is a huge variation to how much weight everybody wears. It is quite amazing.
I have always wondered what happens to gas in the stomach and colon upon ascend. I assume “bean burrito” comment insinuates that, but maybe I am totally wrong and missed something. I guess if one has a bowel obstruction, they really can blow up...
anyhow, as I was working with decreasing my weight, I would get 500psi tank and see if I can hang out at 12-15 feet without trying to squeeze all the air out of my vital capacity. I now dive with no weight in fresh water and 6 lbs in salt. I am usually at a safety stop around 750 to 500. I feel great through 750. I feel a little light but manageable around 500-600. I suppose if I ever get down to 300 it could be problematic without additional weight or a line. It is an intriguing idea to have extra weight available for a safety stop. Has anyone seen this practice in US or Caribbean? Thank you again for all of your expertise. It is cool to hear what everybody does based on geographic location or historical perspective or personal experience. I love this forum.

It was a joke, son....

 

[Eric Sedletzky]

When I started diving in 1975 there was no BCD. We were using twin cylinders, and deco was the norm. Choosing proper weighting was very important, for avoiding to be too negative when at 50m depth the wet suit compresses and the cylinders are yet full of 5 kg of compressed air.
Of course, at the end of the dive and at deco depth one becomes significantly buoyant. The solution was simple: the deco cylinders deployed by the boat when the group was emerging were attached to a bar, together with additional weights. After reaching the bar (usually at 9 or 6 meters, depending on the planned deco) we did attach the additional weights to our belts, and perform the deco in neutral asset.
Some years later I did get my first BCD, an annular Fenzy (you see it in my avatar photo).
But I continued to dive the same way, with little weight, keeping the Fenzy always empty, and relying on the additional weights deployed together with the deco cylinders for buoyancy control during deco.
Here in Italy there is still now a group of divers who do not use any BCD and carefully tune their weights for diving with minimal equipment and friction, using long freediving fins, no suit, or perhaps just a thin wet suit with perfectly smooth external surface (no fabric outside the neoprene) and nothing hanging around.
Here their manifest (in Italian): http://solitarydiver.altervista.org...RA-Lasostenibileleggerezzadellasemplicita.pdf

There is a minimalist movement here in California as well. Mostly it’s the Southern California lobster divers that will dive with no BC’s, long freediving fins, minimal equipment and hoses all tucked in, nothing dangling. They do this to streamline for speed and agility because they need to be fast and to cover a lot of ground.