Proper buoyancy with no lead

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221b

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Location
Texas, USA
# of dives
I just don't log dives
Prior to this morning's quick pool session at a friend's place, I plugged in all numbers in the Optimal Buoyancy calculator spreadsheet and it recommended zero additional lead.
I jumped in the pool this morning to check my buoyancy with all my gear. With zero lead and holding my breath, I sunk just below the surface of the water. The top of my head was prob a few inches to a foot below the surface if I had to guess. Mind you the AL80 tank had about 2500 psi (172 bar) in it. On exhalation I became negative and slowly went to the bottom.
I'm trying to figure out if I should get a lighter backplate in this situation or leave it as is. The backplate I currently have is a Dive Rite stainless XT and is quoted to weigh at 5.5 lbs (2.5 kg). Your thoughts?
 
You're close enough. You're still carrying quite a bit ( 3-4 lbs? ) of heavy air.
 
You're close enough. You're still carrying quite a bit ( 3-4 lbs? ) of heavy air.
Which means you are going to get light at the end of the dive when you have used up that heavy air.
 
should be great, as long as you do not want the option of using heavier - more negative tanks -especially in freshwater. In saltwater, you may need to add 4-5 lbs -if you use an aluminum 80, which should not be a problem.
 
Do you dive in fresh water, you will be more buoyant in salt water? Were you wearing any exposure protection?
 
Do you dive in fresh water, you will be more buoyant in salt water? Were you wearing any exposure protection?

For now just fresh water until later this year/early next when I hit the ocean. I was wearing a full 3 mil for my test today in the pool. Using the calculator again and switching to the "salt" option it says I need about 1 lb. I'll test it out eventually to see if that is correct..
 
The only reason to switch to a lighter plate (with the goal of adding lead) is if you want to adjust your trim by bringing ballast to a lower point.

My stepson is a sinker naturally so we started him on an AL plate just so we could add a couple of pounds to his waist strap pockets to keep him face down.
 
I felt trim in the water but then again I was limited in room to move around. I'll get a good feel for everything hopefully next weekend.
 
The only reason to switch to a lighter plate (with the goal of adding lead) is if you want to adjust your trim by bringing ballast to a lower point.

My stepson is a sinker naturally so we started him on an AL plate just so we could add a couple of pounds to his waist strap pockets to keep him face down.

I prefer a lighter aluminum plate and carrying lead on a weightbelt, so I can drop lead in an emergency. That option is very important to me, maybe less so to others, but certainly something to consider.
 
https://www.shearwater.com/products/swift/

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