If I stop finning, I adopt a vertical position

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Samuurai

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Location
London, UK
# of dives
25 - 49
Hi All,

If I am on a dive and i'm in a horizontal position, while I'm finning, everything is fine, but as soon as I stop, I fairly quickly adopt an upright position. I also noticed that when I try to float on the top of a pool or in the sea, my legs always sink. Short of injecting my ankles with air, what can I do?
 
Move your tank and anything else further up on your body. The more weight that is lower on your body, the more your legs will sink.
 
Basically, you're trim sucks. You have none. Your finning is compensating for lack of trim. When that ceases, your actual trim state is revealed.

Weighting has a lot to do with this. Primarily over-weighting. Second, distribution of weight.

Here's my article on it: Scuba Buoyancy Masterclass 5of9 - Trim and Position -Scuba Tech Philippines
 
I agree, to some degree, with the above. Try working on your weight and tank positioning. But I will say I am in the same situation. Like you, in shorts, in the pool my legs sink like rocks, maybe due to a lifetime of skiing and rowing. Sounds brash but I have excellent buoyancy but I too require the occasional fin flick to keep flat and short of having my tank hit me in the back of the head and weight belt around my chest there is no other solution. Luckily most of my diving is in a drysuit so I can fill my feet up with air, lol.
 
sam also when you stop kicking check if you holding your breathe(air in lungs) also what ever way you look is what way the body will go.

If you can not get it worked out put your weight belt around your neck and you will realize a vertical position is not all that bad!!!!!!!
 
If your BC has trim weight pouches put 2 to4 pounds of weight in them or add some weight to the upper cam band.

I dive with steel tanks and need 4# of weight in weight pouches on my chest to keep in horizontal trim with 18# on my waist.

With steel tanks if I put the trim weights on the cam bands my center of gravity moves so high in the horizontal plain that I turn turtle.
 
The optimal place for some lead is often on the harness and in front of the shoulders. How come nobody seems to manufacture a solution?
 
I will have to disagree slightly with claymore's suggestion. Don't add weight to correct a trim problem, rather shift your current amount of weight to different areas of your body. Not knowing how good your buoyancy is, you might also want to check that as well. Shedding unnecessary kilos of lead will help you out.

If you are weighted correctly, then the following will usually help or even fully correct a trim issue:
- shifting tank position
- shifting weight to center of body (trim pockets, weights on tank straps, or ankle weights around tank valve)
____keep in mind these will be weights you will not be able to ditch*
- hitch your weightbelt higher on your waist
- Body position (adjust how far you extend your legs and arms to shift your center of gravity)
____*planking makes you unstable, being in a sort-of DIR type of position keeps your body weight closer to your CG*
diver_weight.jpg

The point is to put your center of gravity closer to your center of body, indicated by the red arrow in the picture above.
 
Assuming you are wearing proper weight for your configuration, I am in the move it around camp. Trim pocket in the upper area of the BC should be used. You can add trim pockets to the cam band too. Dedicate some dive time in a controlled environment and with a buddy (instructor maybe?) to work on it. Finding one pound weights can be difficult, but well worth it.
 
The optimal place for some lead is often on the harness and in front of the shoulders. How come nobody seems to manufacture a solution?

I've only seen that 'as standard' on sidemount systems. It's a good, direct, solution for trim issues. That said, the same result can be obtained using trim weights on cam-bands, proper weighting and some study/adjustment of body positioning.
 
https://www.shearwater.com/products/peregrine/

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