staying horizontal

[MXGratefulDiver]

A few thoughts to consider ...

- You say you might be overweighted. So don't guess ... find out. The most accurate weight check is done with only your reserve air in the tank ... 500 psi. At a depth of 8 feet (half your safety-stop depth), with all the air out of your BCD, attempt a fin pivot. If you can rise on the inhale and sink on the exhale, you are properly weighted. If you have to add air to your BCD to rise on the inhale, you are overweighted. Remove weights until ... with no air at all in your BCD ... you can rise on the inhale and sink on the exhale.

- Now that you have proper weighting, think about where the weights should be placed. You indicated that you are foot-heavy. This can be resolved in a number of ways. Think of your body like a see-saw, with the pivot at about your waistline. If the foot side of your see-saw is heavy, it can be fixed by moving more weight toward the head side. You can do this by moving weights from the weighbelt and placing them in "trim" pockets on the tank cam band. Or you can (sometimes) move the weight more toward your head by simply sliding your tank a little bit higher on your BCD. Watch that you don't move it so high that it interferes with head movement.

- And finally, consider your body movements. Again, using the see-saw analogy, you can lengthen the "head" side of the see-saw by moving your hands forward ... what I call the "superman position". And you can shorten the foot side by bending your knees, putting your fins closer to your butt. Bending the knees has an additional advantage, in that it gets your fins off the bottom and reduces the potential for stirring up silt or kicking things you'd prefer not to be kicking.

I'd recommend trying each of these things ... in the order presented. Good trim starts with proper weighting. Everything else builds off of that.

... Bob (Grateful Diver)

 

[pasley]

Part of the see saw at the shallow depths of 3 or 4 feet will be......your lungs. Every breath in will raise you up, breath out, and down you go. This was the teaching point of the fin piviot in the pool. (I prefer to use the lotus sitting position and teach my students to maintian a constant depth 1/2 between the surface and the bottom and hold it for 5 or so mintutes.) In the shallow water this will be exhagerated. When doing buoyancy control remember that your lungs are your first tool to use. If you start to rise, exhale, hard. In a swimming pool of 9 feet, if properly weighted you can (should be able to) remain neutral from the shallow end (3 feet) to the deep end (9 feet) using only your lungs. You should be able to decend from surface to a foot off the bottom, stop yourself there and then slowly, very slowly at 30 feet per minute or 6 inches a second ascent to the surface again using only lung control. Remember to not hold the breath, just using the difference between a big breath and a small breath.

 

[boulderjohn]

You have received a lot of very good information about weighting and distribution of that weight already. I just want to add two counterintuitive points that I don't think have been mentioned.

1. You are doing your practice in a very shallow area. The more shallow the water, the harder it is to control buoyancy. If you remember the part of your instruction that talked about the impact of pressure on gas volume, you will see that the shallowest water has the greatest percentage effect. At 100 feet, moving up or down a couple of feet in depth will have little noticeable affect on your buoyancy. At 10 feet it will have a big effect.

2. Being overweighted also makes it harder to control buoyancy, and it is often the reason that many people find themselves shooting to the surface as you describe. People who find themselves shooting to the surface in shallow water often make the mistake of adding more weight, not realizing that it makes things even worse. When you try to get neutral buoyancy, you put enough air in your BCD to balance out the amount of weight you are wearing. If you aren't wearing much of a wet suit, it should take very little air to achieve that balance. The more lead you add, the more air you need in the BCD. The more air you have in your BCD, the more sensitive it is to changes in depth. If you get neutrally buoyant by adding that extra air and then ascend a few feet, you are suddenly shooting to the surface as it expands.

Pasley does a nice job talking about the importance of the lungs. When I teach students in a 12 foot pool, I show them that I can go from the very bottom of the pool to the very top and then back down again simply by controlling the amount of air in my lungs. I can do that even though I am a few pounds overweight in pool instruction. On the other hand, when I am on my own in the pool practicing skills while wearing a steel backplate and double steel tanks, I am very much overweighted. In that same pool I can only control my buoyancy over a few feet with my lungs. There is simply too much air in the wing (BCD) for my lungs to overcome.

 

[DevonDiver]

Take a look at my article on 'Trim and Positioning'. Part of my Buoyancy Masterclass (series of 9)

 

[Ysuboy]

Wow, thank you to all of you. I would reply to every response but I am hoping a collective thank you will suffice. I totally did not expect to get this many well-explained and in-depth (no pun intended) responses. Thank you all and I am sure with everything everyone has shared with me, along with just going out and practicing I will be on my way!

Again, thank you so very much!

 

[ae3753]

All very good advice, here's some articles I wrote too:
Horizontal trim - levers
Horizontal trim - uses

 

[Ysuboy]

awesome! thank you so much! Holy tons of information! I love it! =)

 

[TSandM]

Another tip -- take a look at the 5thD-X videos on YouTube. Body positioning has a lot of effect on trim -- Bob alluded to one effect, which is the lever effect of arm and leg positioning, and Don's articles on Levers address this, too. But another effect is the effect of torso alignment. You will see the divers on the videos I mentioned are FLAT from the shoulders to the knees, and the fine adjustment is with the arms and lower legs and feet. If you are flexing your legs at the hips (like you do to sit down) you will tend to hang feet down -- if you drop your head, you will tend to go head-down. Once you have a flat body, you can play with your extremities to fine tune; if you need to move weight because you can't get horizontal with the weight distribution you have, you'll figure that out.

I can't use Jets in the pool, where I wear a 5 mil suit and use a small aluminum tank, because if I do, my feet will sink.