Buoyancy Issues

[MBH]

I know you asked Carolyn and Perrone, but can I offer some thoughts?

For me, the first key to buoyancy control was the ability to be still. My Fundies instructor told us something that hit seriously home: If you have to be in motion all the time, you aren't balanced. A lot of new divers, because of the feet-down attitude they assume in the water, have to dive with a nasty combination of persistent negative buoyancy and constant finning. The inherent instability in this scenario also results in a lot of swimming with one's hands. Steve told us, "Using your hands is INFORMATION, because you are doing it to try to deal with a buoyancy or balance problem somewhere else. Look at what you are doing -- If you are pushing yourself up with your hands, you're negative; if you're pushing yourself down, you're positive, and if you're only using one hand, you may be unbalanced."

Spending the time to work on hovering -- Hover horizontal and see where you tend to tip. Use a combination of posture and redistribution of weight to get yourself to where you can maintain a horizontal position without major finning or hand waving. (Don't worry if you have to do a little bit. It takes YEARS of practice to be perfectly still, I think!)

Once you have a stable basic platform (horizontal hover), you'll be able to see the effects of the changes you make -- whether that's with breath or BC or attitude or finning -- much more easily, and the learning curve gets MUCH steeper.

I am so thankful that this site provides tons of useful information!!!
Thanks to this thread and posts like Lynne's I cruised through SDI's advanced bouyancy class last night. My HOG rig isn't finished yet so I had to do it in my poodle jacket, but still....8lbs of weight, and 2 tiny puffs in my BC, and 15 minutes later I'm hovering in trim with my feet up and my arms out in front. Not perfect trim mind you, but not horrible either,and I was not flailing around. I learned it here!!! From you fine people!!!!

Here's what I came to realize; as long as I'm concentrating on it, I can hover and hold my trim (in calm water) for a long time. It becomes a whole new ball game once I start task loading. This is going to take LOTS AND LOTS OF PRACTICE!!!

I love it! Thanks folks!

 

[PerroneFord]

Isn't it awesome?! One you really get neutral and hover, you just can't imagine diving any other way.

 

[MBH]

Isn't it awesome?! One you really get neutral and hover, you just can't imagine diving any other way.

Thanks for your input on this. And yes, it is the way to dive! It will also be a good bit easier with my BP/W.

 

[MXGratefulDiver]

OTOH, when my buddy told me I was cockeyed, I adjusted my position and checked him again -- he said fine. To me I was VERY head down -- but this dive gave me the opportunity to "perfectly practice" how it felt to be horizontal in my gear.

I think this is the magic bullet for most. You just cannot BELIEVE how heads down you feel the first time you actually get in trim. You feel like you are doing a head stand. I actually overdid this for about 2 months before Fundies, and had to move back the other way. Now, my trim is pretty good. Back to working on buoyancy!

This is pretty common, actually ... and is an example of the value of a dive buddy to work with (or better yet, a video that'll show you what you look like in the water).

Most of us, when learning good trim, start out thinking that we're horizontal when in fact we're fairly feet-down. It takes some mental adaptation to overcome that "head down" feeling when you reach a horizontal position. Having a buddy to "coach" you into the proper position shortens the learning curve.

In Peter's case, whenever I signaled him that he was out of trim he'd adjust his position to horizontal and hold it just fine for a while. As the dive went on, I had to signal less and less ... and by the end of the dive, not at all. That tells me the skills are there ... it's just a matter giving your brain a chance to adapt to how it feels.

Once you get to that point, attaining good trim starts to become automatic ...

... Bob (Grateful Diver)

 

[MBH]

Most of us, when learning good trim, start out thinking that we're horizontal when in fact we're fairly feet-down. It takes some mental adaptation to overcome that "head down" feeling when you reach a horizontal position. Having a buddy to "coach" you into the proper position shortens the learning curve.

... Bob (Grateful Diver)

I'm glad you mentioned that. Even with my feet "up" they still felt too low for my likes. I had to adjust my BC until the trim pockets were up on my shoulder blades. Only then did I begin to feel like I was getting my trim right. I didn't have the head down feeling so perhaps I still wasn't quite right.

Unfortunately, teaching proper trim wasn't on last nights agenda so I had to do the best that I could.

 

[MXGratefulDiver]

I'm glad you mentioned that. Even with my feet "up" they still felt too low for my likes. I had to adjust my BC until the trim pockets were up on my shoulder blades. Only then did I begin to feel like I was getting my trim right. I didn't have the head down feeling so perhaps I still wasn't quite right.

Unfortunately, teaching proper trim wasn't on last nights agenda so I had to do the best that I could.

Consider, if possible, moving your cylinder higher on the BCD. Sometimes ... especially with more traditional, or single-strap BCDs ... the cylinder is mounted such that it's very low on the diver's body. This will affect your trim dramatically. Even moving it upward an inch can have a significant impact on your trim.

Without seeing how your rig is configured, this may or may not be helpful advice ... but it's often the case that people with trim issues can benefit by simply adjusting the position of their cylinder.

... Bob (Grateful Diver)

 

[MBH]

Good Idea Bob, I was thinking about that while driving home last night. I'm also thinking that I might adjust my BP/W up a little higher. All I need is my long hose and a back up reg and I'm out of my BC forever.

 

[dry heat diver]

My wife and I completed our pool dives last week. Most of the skills were no problem - mask flooding/clearing, sharing air, regulator/snorkel exchanges were a piece of cake. Our weight was perfect - eye level floats, etc. However, both of us seemed to have a lot of trouble with buoyancy. It seemed every time we took a breath, we headed for the surface! Attempting to do fin pivots was very frustrating. I could lie on the bottom of the pool, and inhale a little, and before I could exhale, I had already floated completely off the bottom. It didn't help that we and one other guy were the only adults in the class who had never been underwater before. The rest of the group was doing refreshers. Talk about sticking out like sore thumbs! Most of the people in the session could kneel on the bottom of the pool with no problems whatsoever, but it seemed like we were floundering about like beached whales!

Most of the people I've talked to since have tried to encourage me by saying that everyone has trouble with buoyancy until they have a few dives under their belt. However, we are planning to do our open water certification dives as a referral in Puerto Rico in April while we are on vacation. We don't want to be the only ones in the OW class who can't seem to stay in one place for longer than a few seconds at a time. As a matter of fact, I've asked our instructor to let us do the pool dives again just to see if we can do a little better the second time around. He says he doesn't worry about our safety and is comfortable with referring us for our OW dives, but I just don't have the self-confidence I thought I'd have.

What do some of you old-timers think about our concerns?

Thanks,
Mike

Stay wet and work on refining your skills as often as possible before your trip. Also consider doing the OW cert before you go. It will allow you to enjoy the vacation trip more without being constantly focused on the cert process.

 

[Texasdivechick]

I was just OW certified this weekend and I had trouble with buoyancy as well. I could kneel on the platform at 35', but while swimming around in murky water I was all over the place and ended up sliding down a trench. Thank goodness I was just in a lake with alot of tree branches underwater, not pristine coral. However, I am headed to Bonaire in a few weeks and I REALLY don't want to disturb the underwater environment. It was good to read the threads here. I think I will practice in a pool again, and hire a dive master when I get there just to help establish buoyancy in different salinity. Thanks for all the good advice.

 

[neil]

Together (hehe), we arrived at the conclusion that the larger bubble changed volume in response to changes in his grip pressure much more than the smaller bubble, as it was, well, larger.

That doesn't sound right.
All things being equal, if both Cartesian divers are truly adjusted to the exact same bouyancy, then an equal amount of hand pressure on the bottles should control each one similarly. Double the pressure, halve the volume, as an example, no matter what size the bubble is. But, what do I know?

Try making your Cartesian divers out of little diver shaped cutouts made of neoprene. Get them just positive using solder as "weight belts". You may have to put some on the legs also. This makes more of an impact than using eye droppers, since of course divers wear neoprene, not eye droppers.