Balanced buoyancy advice please

[Frosty]

Folks for tropical diving Im struggling with balanced boyancy control. My feet drop when I'm at rest.
I'm wearing a 3mm steamer,WI BC with 5kg of lead. My fins are slightly negatively boyant.
I've asked this question before and have acted on your advice but the issue is still there.
I have moved the cylinder as far up as I can. Ive moved 2kg lead from hip pockets up to the tank strap and still my feet drop. I'm at the point of changing fins just to get a set that are boyant as this is the only solution I can think of havent tried.
Any other ideas greatly apreciated

 

[TSandM]

Well, how is your posture? The bottom line for balance is body position -- head up, body flat from shoulders to knees, knees bent to the degree required by the configuration. If you drop your knees, you will tilt feet down, almost no matter what you do with your weights.

I can dive Jets with spring straps, which are quite negative, with an Al80 in warm water, without being committed to being feet down. But I have good posture, and I put my arms out in front of me. I use two pounds on the cambands, and a steel backplate.

 

[waterpirate]

Start borrowing some fins and see what happens. I found my oms slipstreams to be a good fin but made my feet sink. I tried a pair of jets and presto good feet position. YMMV
Eric

 

[krawlings]

Start borrowing some fins and see what happens. I found my oms slipstreams to be a good fin but made my feet sink. I tried a pair of jets and presto good feet position. YMMV
Eric

that is strange the Jets are negative and the OMS slipstreams are neutral

 

[DevonDiver]

Two issues effect this:

1) Total weighting.

2) Distribution of weighting.

When I say "weighting" I mean the total composition of positively and negatively buoyant mass within, or attached to, your body... not just lead ballast.

Total weighting: Specifically in terms of ballast weighting, any tendency to over-weight yourself will cause 'feet-down' trim. The hips are below the general center of gravity/mass - so weight here pulls the lower body downwards. Divers compensate for being over-weighted by adding air to the BCD.. this is above the center of gravity/mass. Thus, a 'push-pull' effect is created that tends to pull the diver towards the upright. Pay as much attention to the air in your BCD as you do to the weight on your belt.

Add to this non-ballast weighting consideration. Jacket style BCDs are typically quite 'floaty'.... you pay a trim price for all that lovely padding and plastic. You fins may be negative... and they're stuck waaay-dooown at the bottom of your body fulcrum... having a distinct impact on your center-of-gravity and thus, your trim.

Your body itself has an impact, making positioning important. Experiment with foot, arm and head positioning for effect. Typical 'good posture' to enable horizontal trim is very similar to 'freefall parachutist' position.... legs up vertical from the knees, arms in front, head high and back arched.

 

[billgraham]

Trim weights on shoulder straps?

 

[danvolker]

Darth Vader Helmet weighing 6 pounds, with built in mask and regulator

 

[UnderwaterMedic]

I would just spend a lot of time at the pool. Try the suggestions there, and keep tinkering until you get it. Focus on the whole picture as Devon pointed out above. Also, if possible, have someone record your attempts using an underwater camera or gopro or something. Then watch the video and analyze where you can improve. I know that for one helped me out a ton in that regard. Good luck

 

[fjpatrum]

I have been practicing my buoyancy and trim on my last few dives and I find TSandM's advice pretty well spot on, as long as I'm not over or under weighted. When I'm diligent about keeping a nice clean line from my shoulders to my knees, I have far fewer "issues" maintaining my buoyancy. Being over or under weighted is also much easier for me to recognize that way.

There have been several links posted to I think 5th dimension tutorials about body fulcrums and such but I don't have any of the links handy. Very good reading though. So far I've been able to use my saekodive full foot fins, Tusa Extreme 3 splits, and Mares Quattros which all have significantly different buoyancy characteristics and keep my position relatively constant (and hopefully correct) by paying close attention to my body posture.

 

[TSandM]

I think this may be the link you are talking about: Deep-Sea Sherpa » Horizontal Trim 101 – Levers

Don has a lot of good stuff on his site.