Diving without BCD?

[Storker]

Where's the moderators...

Several of them are in this thread and are thus recused from moderating it.

Besides, there has been no reports of posts violating the ToS, and the Scubaboard Mod Corps don't moderate for content, value nor sense. Only on the basis of ToS violations.

 

[Sam Miller III]

I would suggest that you cease posting -- Immediately !
I responded to Mr. Meixner as follows

"History of the wet suit deleted

Just to keep @W W Meixner happy
Strongly suggest all the other posters also delete all posts not directly and specially related to the OP original question --

We must at all cost keep @W W Meixner happy -- SCUBA Board can not allow a cardiac event as a result of an early AM informative fun post

To learn about the accidental discovery of the wet suit; it becoming a secret Korean war item and it introduction into the civilian market please contact @W W Meixner

Or purchase my forth coming book " The was it was... SCUBA stories for my friends"

SDM"

I might ad - K MAG YO YO..
sdm

 

[drbill]

Dove without one for 29 years. First time I used one it was required equipment on a dive with a Cousteau dive team. The darn thing kept autoinflating. The DM asked what we should do and I said disconnect it. She was surprised at my response but the dive went on flawlessly. Back in the 60s and 70s some of my students had Mae West but I couldn't afford one on a teacher's salary.

 

[dmaziuk]

Sorry, don't understand. What does tank capacity have to do with the weight of the gas that you consume during a dive?

A: time, as in dive time. Your premise is you consume fixed amount of gas out of any size tank. The difference in question is between breathing a LP72 vs. double-HP120s dry.

 

[doctormike]

A: time, as in dive time. Your premise is you consume fixed amount of gas out of any size tank. The difference in question is between breathing a LP72 vs. double-HP120s dry.

I'm actually surprised that this point keeps being made. If you are comparing the difference in buoyancy swing between two tanks, it makes no sense to compare two different dives.

But lets consider your proposition. Which tank material has the larger buoyancy swing, aluminum or steel?

Comparing an AL100 to a steel 72 (at service pressures), that would mean that the AL100 has the bigger buoyancy swing, since you can breathe a greater weight of gas from it. But comparing an steel 130 to an AL80, you can breathe a greater weight of gas from the steel tank before it is dry.

So which tank material has a bigger buoyancy swing, based on the above - steel or aluminum?

Of course, the answer is that for a given dive, tank material and capacity have no effect on buoyancy swing. If you want to minimize your buoyancy swing (as was referenced upthread) there is only one way of doing that - breathe less gas by doing a shorter dive, a shallower diver or working on your SAC.

 

[Bob DBF]

A bc is a necessary tool in my opinion because they exist, are readily available and are often practically given away on the used market. I believe that if a person is asking the question of whether a bc is necessary then the answer is absolutely yes. The real answer; however, is it depends.

Scuba training used to cover training without a BC because there were none, today the training is done with a BC. The differences can kill a diver who doesn't learn those differences before diving without them. The first would be proper weighting, which is a crap shoot in today's OW training.

Buoyancy swing depends only on the amount of gas you've used during the dive.

My wet suit buoyancy does not rebound to the same positive buoyancy it had at the start of the dive, it depends on depth and time at depth, a couple of pounds is not unusual. Eventually I replace the suit because it quits rebounding at all and has lost its insulating properties as well.


Bob

 

[dmaziuk]

If you want to minimize your buoyancy swing (as was referenced upthread) there is only one way of doing that - breathe less gas by doing a shorter dive, a shallower diver or working on your SAC.

Yep: dive an LP72 and you get your shorter dive.

 

[Storker]

My wet suit buoyancy does not rebound to the same positive buoyancy it had at the start of the dive, it depends on depth and time at depth, a couple of pounds is not unusual. Eventually I replace the suit because it quits rebounding at all and has lost its insulating properties as well.

Ok, I'll claim ignorance and accept your claim unless compelling evidence to the contrary is presented. I have very little experience with diving wet; almost all of my dives have been (mostly) dry.

But seriously, how are you able to notice a 2lb/1kg difference in your buoyancy? I most probably couldn't.

 

[Bob DBF]

But seriously, how are you able to notice a 2lb/1kg difference in your buoyancy? I most probably couldn't.

I do a weight check, empty BC at 15' with 500# in the tank, on a regular basis, like most dives, and have a few of 1# weights to adjust if necessary. It's overkill, but I also freedive and scuba dive without a BC, where it can be important. It's not that I dive perfectly weighted all the time, I just want to know what is right before I change anything.

I could see how it might be harder to notice a difference in buoyancy with two air bubbles to juggle.



Bob

 

[RayfromTX]

I notice 2 lbs at the end of a dive and at the beginning. It's half a lung of air mas o menos. If I can sink at the beginning by emptying my bc without exhaling, I have more weight than I need. If I can hold a safety stop with a small bubble in my wing and a lung full of air then that's too much. If I have an empty wing at the end and have to breathe on the bottom of my lungs to hold the stop then I could use a couple more pounds.